A cloud of questions hangs over the claim.

Why did the Kremlin announcement come about 12 hours after the purported incident? Why did no reports of explosions emerge prior to the announcement on the messaging apps that remain full of chatter despite Russia’s crackdown on media and criticism of the war in Ukraine? Why didn’t videos of the purported attacks appear until after the announcement? Why haven’t the images been verified?

A drone attack on the Kremlin would be the most severe penetration of Russian airspace since German teen Matthias Rust landed his little single-engine plane on the fringes of Red Square in 1987. Announcing the attack — or even faking it — risks Russia undermining its citizens’ trust in its frequent assertions of military superiority.

Adding to that humiliation is that the incident occurred less than a week before Victory Day, Russia’s paramount military holiday. In some of the videos of the claimed attack, the decorated viewing stands and tribune for the day’s ritual Red Square military parade can be seen prominently.

For President Vladimir Putin, the confession of Ukrainian drones reaching the Kremlin could be justification for a brutal step-up of attacks on Ukraine. Russian officials persistently contend — repeated evidence to the contrary — that the military goes after only military targets.

Severe retaliation is already in the wind, including threats aimed specifically at Ukrainian President Volodymyr Zelenskyy, who denied attacking the Kremlin.

“After today’s terrorist act, no variant remains other than the physical elimination of Zelenskyy and his clique,” said former Russian president and deputy chairman of the Russian security council, Dmitry Medvedev,

The chairman of the powerful lower house of parliament, Vyacheslav Volodin, compared the Ukrainian government with the terrorist Islamic State and said he will demand “the use of weapons capable of destroying it.”

Russia’s nuclear doctrine says the country can use nuclear weapons if it comes under a nuclear strike or if it faces an attack with conventional weapons that threatens “the very existence” of the Russian state. The West has accused Putin of nuclear saber-rattling during the Ukraine war

But Phillips O’Brien, a professor of strategic studies at University of St. Andrews, downplayed the possibility related to the alleged Kremlin attack.

“You’re not going to say, ‘Now that there has been an attack with a tiny drone, now we can go nuclear,’” he said.

Commentator Abbas Gallyamov, a former Putin speechwriter who has fled the country, also raised doubts.

“If enemy drones reach the Kremlin, it means that any other object on the territory of the European part of Russia is generally defenseless,” he said. “Therefore, I do not believe that this was a provocation conceived by the Kremlin in order to influence public opinion.”

If Ukraine had indeed attacked, “consider it a performative strike, a demonstration of capability and a declaration of intent: Don’t think Moscow is safe,” said Mark Galeotti, a Russian military and security analyst at University College, London.

Less clear, he said on Twitter, “is whether it shakes Russians’ nerve or angers them.”

Russians’ nerves already have been frayed by attacks, either likely from Ukraine or from domestic opponents, that have risen sharply in recent weeks.

Two freight trains derailed this week in bomb explosions in the Bryansk region that borders Ukraine. Notably, the region’s authorities did not blame Ukraine, which could be an attempt to whitewash Ukrainian sabotage capacities.

But Bryansk authorities in March claimed that two people were shot and killed when alleged Ukrainian saboteurs penetrated the region. The region also has been hit with sporadic cross-border shelling, including one that killed four people in April.

Ukrainian drones reportedly have penetrated deep into Russia several times. In December, Russia claimed to have shot down drones at airfields in the Saratov and Ryazan regions. Three soldiers were reported killed in the attack in Saratov, which targeted an important military airfield.

Earlier, Russia reported shooting down a Ukrainian drone that targeted the headquarters of its Black Sea Fleet in Sevastopol in Russia-annexed Crimea.

In addition, two prominent supporters of Russia’s war in Ukraine have been killed on their home ground. Darya Dugina, a commentator with a nationalist TV channel, died in a car bombing outside Moscow that officials blamed on Ukraine. And authorities said Ukrainian intelligence was behind the killing of prominent pro-war blogger Vladlen Tatarsky, who was killed in April when a bomb inside a statuette he was handed at a party exploded.

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Follow AP’s coverage of the war in Ukraine at https://apnews.com/hub/russia-ukraine

Russian President Vladimir Putin announced last week that the country would suspend participation in the New START treaty which obligated both Russia and the U.S. to commit to regular communications on the status of their nuclear arsenals, allow regular on-site inspections and abide by caps on the number of deployed and non-deployed warheads of each side.

“Russia is once again showing the world that it is not a responsible nuclear power,” Bonnie Jenkins, the U.S. undersecretary of state for arms control, said at a session of the Conference on Disarmament, a United Nations-affiliated international forum.

Russia is not withdrawing from the treaty, which is in force until 2026, but Putin said Russia cannot accept U.S. inspections of its nuclear sites while Washington and its NATO allies seek Russia’s defeat in Ukraine. The Russian Foreign Ministry said the country would respect the treaty’s caps on nuclear weapons and continue notifying the U.S. about test launches of ballistic missiles.

The inspections have been dormant since 2020 because of the COVID-19 pandemic. Discussions on resuming them were supposed to have taken place last November, but Russia abruptly called them off.

Jenkins later told reporters that the U.S. has not fully assessed the consequences of Russia’s suspension move, but said “we’re not seeing any evidence that Russia is in noncompliance.”

“We remain ready to work assertively with Russia to fully implement the New START treaty, continued implementation of the treaty based on the best interests of both parties,” she said.

Putin’s announcement of suspending participation came just before the first anniversary of Russia sending troops into Ukraine. Putin has repeatedly cast the conflict as necessary to combat alleged Western aims to weaken Russia and has warned of an increasing threat of nuclear war.

Former Russian president Dmitry Medvedev, now deputy head of the national security council, said last week that “If the U.S. wants Russia’s defeat, we have the right to defend ourselves with any weapons, including nuclear.”

“Russia must end this war and must cease its irresponsible nuclear rhetoric,” Jenkins said.

French Foreign Minister Catherine Colonna also harshly criticized Russia’s New START suspension at the Geneva conference as “added proof — if any was needed — of the dangerous impasse that Russia is sealing itself into.”

Jim Heintz reported from Moscow

Whelan’s brother, David, said in an emailed statement that Paul had called his parents early U.S. time on Friday, the first time any family member had spoken with him since Nov. 23. The family had been told that he was moved to a prison hospital, but that the reason for that was unclear because he had not spoken of health problems.

In the call, he did not explain why he was at the hospital, but said he’d been given “special dispensation” to call, indicating he had been prohibited from calling previously, David Whelan said.

“So the call at least acts as a ‘proof of life’ even if nothing else is explained,” he said.

Alexei Tyurkin, the chairman of the prison monitoring commission in the Mordovia region where Whelan is incarcerated, said he was in the prison hospital for “planned treatment,” but did not elaborate, according to state news agency RIA-Novosti.

The State Department said later that Whelan also spoke to U.S. consular officers and that he had been returned from the hospital to the prison colony itself.

Whelan, who worked as a corporate security executive, was arrested in Moscow in December 2018. His lawyer said Whelan was handed a flash drive that had classified information on it that he didn’t know about.

Whelan was convicted in 2020 and sentenced to 16 years in prison.

Along with WNBA star Brittney Griner, Whelan is the focus of efforts by the United States to arrange a prisoner swap with Russia.

The Associated Press and other news organizations have reported that Washington has offered to exchange Griner and Whelan for Viktor Bout, a Russian arms dealer who is serving a 25-year sentence in the U.S. and once earned the nickname the “merchant of death.”

Griner was sentenced to nine years in prison in August for drug possession after vape canisters containing cannabis oil were found in her luggage at a Moscow airport in February. Her prominence as an athlete, including two Olympic gold medals, has drawn wide attention to her case.

Asked by reporters on Tuesday whether a swap is possible before the year’s end, Russia’s deputy foreign minister, Sergei Ryabkov, responded: “There always is a chance.”

“Regrettably, there have been a few occasions when it seemed that a decision in favor of it was about to be made, but it never happened,” Ryabkov said without elaborating.

Biden will ban Russia from US airspace amid Ukraine invasion, sources say

7:50 p.m. EST March 1

President Joe Biden will vow to make Vladimir Putin “pay a price” for Russia’s invasion of Ukraine in his first State of the Union address, rallying allies abroad while also outlining his plans at home to fight inflation and the fading but still dangerous coronavirus.

In addition to recounting U.S. and allied economic sanctions against Russia, Biden planned to announce that the U.S. is following Canada and the European Union in banning Russian planes from its airspace in retaliation for the invasion of Ukraine, according to two people familiar with his remarks. They spoke only on the condition of anonymity before the speech.

Biden planned in his Tuesday night remarks to highlight the bravery of Ukrainian defenders and the resolve of a newly reinvigorated Western alliance that has worked to rearm the Ukrainian military and cripple Russia’s economy through sanctions. He was set to deliver an ominous warning that without consequences, Russian President Putin’s aggression wouldn’t be contained to Ukraine.

“Throughout our history we’ve learned this lesson – when dictators do not pay a price for their aggression, they cause more chaos,” Biden was to say, according to advance excerpts released by the White House. “They keep moving. And, the costs and threats to America and the world keep rising.”

Even before the Russian invasion sent energy costs skyrocketing, prices for American families had been rising, and the COVID-19 pandemic continues to hurt families and the country’s economy.

Biden planned to outline plans to address inflation by reinvesting in American manufacturing capacity, speeding supply chains and reducing the burden of childcare and eldercare on workers.

“We have a choice,” Biden was to say. “One way to fight inflation is to drive down wages and make Americans poorer. I have a better plan to fight inflation. Lower your costs, not your wages.”

Set against disquiet at home and danger abroad, the White House had conceived Tuesday night’s speech as an opportunity to highlight the improving coronavirus outlook, rebrand Biden’s domestic policy priorities and show a path to lower costs for families grappling with soaring inflation. But it has taken on new significance with last week’s Russian invasion of Ukraine and nuclear saber-rattling by Putin.

In an interview with CNN and Reuters, Zelenskyy said he urged Biden to deliver a strong and “useful” message about Russia’s invasion. Ahead of the speech, the White House announced that Ukrainian Ambassador to the U.S. Oksana Markarova would join first lady Jill Biden in the galleries to watch Biden’s address.

Russian troops step up attacks on urban areas

6:35 p.m. EST March 1

Russian forces escalated their attacks on crowded urban areas Tuesday, bombarding the central square in Ukraine’s second-biggest city and Kyiv’s main TV tower in what the country’s president called a blatant campaign of terror.

“Nobody will forgive. Nobody will forget,” President Volodymyr Zelenskyy vowed after the bloodshed on the square in Kharkiv.

Ukrainian authorities said five people were killed in the attack on the TV tower, which is a couple of miles from central Kyiv and a short walk from numerous apartment buildings. A TV control room and power substation were hit, and at least some Ukrainian channels briefly stopped broadcasting, officials said.

Zelenskyy’s office also reported a powerful missile attack on the site of the Babi Yar Holocaust memorial, near the tower. A spokesman for the memorial said a Jewish cemetery at the site, where Nazi occupiers killed more than 33,000 Jews over two days in 1941, was damaged, but the extent would not be clear until daylight.

At the same time, a 40-mile (64-kilometer) convoy of hundreds of Russian tanks and other vehicles advanced slowly on Kyiv, the capital city of nearly 3 million people, in what the West feared was a bid by Russian President Vladimir Putin to topple the government and install a Kremlin-friendly regime.

The invading forces also pressed their assault on other towns and cities, including the strategic ports of Odesa and Mariupol in the south.

Day 6 of the biggest ground war in Europe since World War II found Russia increasingly isolated, beset by tough sanctions that have thrown its economy into turmoil and left the country practically friendless, apart from a few nations like China, Belarus and North Korea.

As the fighting in Ukraine raged, the death toll remained unclear. One senior Western intelligence official estimated that more than 5,000 Russian soldiers had been captured or killed. Ukraine gave no overall estimate of troop losses.

Britain’s Defense Ministry said it had seen an increase in Russian air and artillery strikes on populated urban areas over the past two days. It also said three cities — Kharkiv, Kherson and Mariupol — were encircled by Russian forces.

‘Concrete evidence’ Russia using cluster munitions, rights groups say

3:25 p.m. EST March 1

Rights groups and observers say Russia is using cluster bombs in its invasion of Ukraine, a charge Moscow denies. If confirmed, deployment of the weapon, especially in crowded civilian areas, would usher in new humanitarian concerns in the conflict, Europe’s largest ground war in generations.

Proponents of banning cluster bombs say they kill indiscriminately and endanger civilians long after their use. From Syria and Yemen to the Balkans, Afghanistan and Southeast Asia, unexploded ordnance from cluster bombs continues to kill and maim people years or even decades after the munitions were fired.

Though many countries have joined a global convention limiting their use, cluster munitions are still used in conflict zones around the world.

Here is a closer look at the weapon and why its use sparks particular concern:

WHAT IS A CLUSTER BOMB?

Cluster bombs are weapons that open in the air, releasing submunitions, or “bomblets,” that are dispersed over a large area, intended to wreak destruction on multiple targets at once. Cluster bombs can be delivered by planes, artillery and missiles, according to the International Committee of the Red Cross.

Beyond the initial harm caused by the munitions upon impact, bomblets have a high rate of failure to explode, up to 40% in some recent conflicts, according to the ICRC.

That leaves swaths of land dotted with bomblets that could explode. Return to normal life in those areas becomes hazardous, particularly in heavily populated areas. Some formerly war-torn countries spend years trying to clear unexploded cluster bomblets.

IS USING THEM A WAR CRIME?

Use of cluster bombs itself does not violate international law, but using them against civilians can be a violation. As in any strike, determining a war crime requires looking at whether the target was legitimate and if precautions were taken to avoid civilian casualties.

“The part of international law where this starts playing (a role), though is indiscriminate attacks targeting civilians,” Human Rights Watch’s associate arms director Mark Hiznay told The Associated Press. “So that’s not necessarily related to the weapons, but the way the weapons are used.”

A convention banning the use of cluster bombs has been joined by more than 120 countries who agreed not to use, produce, transfer or stockpile the weapons and to clear them after they’ve been used.

Russia and Ukraine have not joined that convention. Neither has the United States.

WHERE HAVE THEY BEEN USED?

The bombs have been deployed in many recent conflicts.

Syrian government troops have often used cluster munitions — supplied by Russia — against opposition strongholds during that country’s civil war, frequently hitting civilian targets and infrastructure.

Israel has used cluster bombs in civilian areas in south Lebanon, including during the 1982 invasion that saw Israeli troops reach the capital Beirut.

During the monthlong 2006 war with Hezbollah, Human Rights Watch and the United Nations accused Israel of firing as many as 4 million cluster munitions into Lebanon. That has left unexploded ordnance that threatens Lebanese civilians to this day.

The Saudi-led coalition in Yemen has been criticized for its use of cluster bombs in the war with the Iran-backed Houthi rebels that has ravaged the southern Arabian country.

In 2017, Yemen was the second deadliest country for cluster munitions after Syria, according to the U.N. Children have been killed or maimed long after the munitions originally fell, making it difficult to know the true toll.

The last large-scale American use of cluster bombs was during the 2003 Iraq invasion, according to the Pentagon. The U.S. initially considered cluster bombs an integral part of its arsenal during the invasion of Afghanistan that began in 2001, according to HRW. In the first three years, it is estimated the U.S.-led coalition dropped more than 1,500 cluster bombs in Afghanistan.

The U.S. Defense Department had been due by 2019 to stop use of any cluster munitions with a rate of unexploded ordnance greater than 1%. But the Trump Administration rolled back that policy, allowing commanders to approve use of such munitions.

Cluster munitions were also used in the Balkan wars in the 1990s. In the 1980s the Russians made heavy use of cluster bombs during its 10-year invasion of Afghanistan. As a result of decades of war, the Afghan countryside remains one of the heaviest mined countries in the world.

WHAT’S HAPPENING IN UKRAINE?

Russian forces have “most definitely” used cluster bombs in Ukraine, Human Rights Watch’s Hiznay said.

He pointed to at least two instances: a missile attack that hit outside a hospital in the town of Vuhledar on the first day of the invasion last week. and another Monday on Ukraine’s second largest city, Kharkiv, with a population of 1.4 million.

Hiznay retweeted photos of what he said was unexploded 9N235 cluster submunitions scattered around in Kharkiv. Human Rights Watch said four people were killed in the Vuhledar strike.

Rights groups have said three people were killed after Russian cluster bombs hit near a pre-school in the northeastern city of Okhtyrka. The open-source intelligence group Bellingcat says that its researchers found cluster munitions in that strike as well as multiple cluster attacks in Kharkiv.

Amnesty International said Russian forces have a “shameful record of using cluster munitions in populated areas.”

Justin Bronk, a research fellow at Royal United Services Institute, a London defense think tank, said images of munitions parts recovered from residential areas of Kharkiv are “concrete evidence” that Russia is using cluster bombs.

“Their use suggests the Russians are trying to break morale, inflict terror on the on the civilian population and the defenders in order to try and force a negotiation or just retreat,” he said.

Russia denies using cluster munitions in Ukraine.

Russian advance on Kyiv at a standstill, US official says

11:54 a.m. EST March 1

Russian troops staged around the outside of Ukraine’s capital city appear to be in a holding pattern of some kind, a senior U.S. defense official told reporters Tuesday.

Formations that had been moving toward Kyiv are essentially in the same spot today as they were Monday, the official sending, roughly 17 miles outside the city center.

“We believe that that’s for a number of reasons,” the official said. “Obviously, the resistance that they’re facing, the fuel and sustainment problems that they’re having. We are also picking up signs that they’re having problems feeding their troops, that they’re not only they’re running out of gas, but they are running out of food.”

The Pentagon’s assessment echoes multiple reports from recent days, that Russian troops are looking for fuel and sustenance as they roll toward Kyiv.

There’s also the possibility, the official said, that the Russians are taking a strategic pause to regroup after a possibly unanticipated defense from the Ukrainian armed forces.

“There has been in the last six days evidence of a certain risk-averse behavior by the Russian military,” the official said. “Now I say risk-averse, I mean risk to their own force.”

Without commenting on whether Russia’s initial invasion plans have been upended, the official echoed other media reports that many of the Russian troops seem ill-prepared for the fight.

“We do believe that a significant number of them are conscripts — very young men drafted into service,” the official said. “And apparently … not all of them were apparently fully trained and prepared or even aware that they were going to be sent in to a combat operation.”

The official said that while the Pentagon assesses that the Russians have launcher systems that could be used for a thermobaric weapons, “we cannot confirm the presence of a thermobaric weapon and we cannot confirm the use of a thermobaric weapons, but we certainly believe that they have the launching systems capable of using basically a fuel air explosive that’s fired by rocket.

The Pentagon doesn’t believe that Belarusian troops have entered Ukraine, the official said.

Russia has raised the specter of nuclear war

11:35 a.m. EST March 1

NATO’s chief said Tuesday that, despite Russia’s threats about nuclear weapons, the alliance sees no need to change its own nuclear weapons alert level.

The alliance’s secretary-general, Jens Stoltenberg, spoke to The Associated Press following talks on European security with Polish President Andrzej Duda at an air base in Lask, central Poland, where NATO’s Polish and U.S. fighter jets F-15 and F-16 are based.

“We will always do what is needed to protect and defend our allies, but we don’t think there is any need now to change the alert levels of NATO’s nuclear forces,” Stoltenberg said.

The Kremlin began an invasion of Ukraine last week and on Tuesday shelled the center of the Ukrainian city of Kharkiv. Russia has raised the specter of nuclear war, reporting on Monday that its land, air and sea nuclear forces were on high alert following President Vladimir Putin’s weekend order. NATO itself has no nuclear weapons, but three of its members do — the United States, Britain and France.

“We strongly believe it’s reckless and irresponsible the way Russia is speaking about nuclear weapons,” Stoltenberg said, standing in one of the base’s hangars, which has been turned into a conference room with Polish and NATO flags and jets around it.

Stoltenberg stressed that Russia has signed a number of deals agreeing that nuclear war cannot be won and should not be fought.

He called on Russia to “stop the attacks and withdraw all its forces and engage in good faith in diplomatic efforts” to end the war.

Government delegations from Ukraine and Russia met for talks in southeastern Belarus on Monday, but the outcome was not immediately clear.

“This is a horrendous, horrific invasion of an innocent country and we see that civilians are killed. It’s a brutality that has to stop immediately,” Stoltenberg said.

The United States recently reinforced the eastern flank of NATO’s territory with some 5,000 additional troops deployed to Poland and Romania. Both NATO countries border Ukraine, which is not part of NATO. A number of French troops were traveling to Romania on Tuesday to further strengthen the region, Stoltenberg said.

The alliance is to discuss further reinforcement steps at its next summit in June in Madrid.

It is NATO’s responsibility to “ensure that we don’t see a development where a conflict in Ukraine spiraled out of control and becomes a full-fledged confrontation between NATO and Russia in Europe,” Stoltenberg said.

He said alliance commanders are insisting that they are “able to maintain deconfliction (contacts) with Russia,” he said.

From Lask, Stoltenberg flew to Tallin, Estonia, for talks on security of the Baltic region which borders Russia and its ally Belarus.

President Zelenskyy appeals for EU membership

7:51 a.m. EST March 1

From his embattled capital city under intense Russian attack, Ukraine President Volodymyr Zelenskyy delivered an impassioned speech to the European Parliament Tuesday, seeking approval to join the European Union.

“The last couple of days, I don’t know how to welcome and greet everybody because I cannot say good morning,” he said through an interpreter. “Or I cannot say good afternoon or good evening. And I cannot and that’s true. Because every day for some people, this day is not good. For some people this day is the last one. I speak today now about my citizens of Ukraine who are defending and paid the ultimate price. They are defending freedom.

“I don’t read off the paper,” he continued. “Because paper fades in the life of my country and now we’re dealing with reality. We’re dealing with killed people. And, you know, I believe that today we’re giving lives for families. For the right for freedom. For the desire to be equal as much as you are. We’re giving away our best people. The strongest ones. the most value-based ones. Ukrainians are incredible.”

This was a difficult morning, Zelenskyy said.

“This morning was a very tragic one for us,” he said. “Two cruise missiles hit Kharkiv, the city, which is located [near] the borders of the Russian federation.”

Kharkiv, he said, is a city with many Russians who enjoyed friendly relations with Ukrainians.

“There are more than 20 universities are there,” he said. “It’s the city that has the largest number of universities in our country. Bright, smart people who gathered there all the time for celebrations, and the largest square in our country. The Freedom Square. And this is the largest square in Europe and that’s true. This is called the Freedom Square. Can you imagine this morning two cruise missiles hit this Freedom Square. Dozens were killed. This is the price of freedom.”

Ukrainians, said Zelenksyy, “are fighting for our land. For our freedom despite the fact that all large cities of our country are now blocked. Nobody is going to answer and intervene without freedom and believe you me every square up to date, no matter what it’s called, it’s going to be called as of today. Freedom Square.”

Zelenskyy said his country would stand strong in the face of difficult odds as Russian forces hit cities with missiles and airstrikes, and a long column of troops and supplies wends its way closer to Kyiv.

“Nobody is going to break us,” he said. “We are strong. We are Ukrainians. We have a desire to see our children. Alive. I think it’s a fair one. Yesterday 16 children were killed. Again and again. President Putin is going to say that is some kind of operation and we are hitting a military infrastructure. Where our children? What kind of military factories do they work at? What tanks are they going with? Launching cruise missiles, he killed 16 people just yesterday.”

Despite the odds, Ukrainians “are very much motivated, very much so,” Zelenskyy said. “We are fighting for our rights. For our freedoms. For our life and now we’re fighting for our survival.”

And that, he said, “is the highest of our motivation. But we are fighting also to be equal members of Europe. I believe that today. We are showing everybody that’s exactly what we are.”

The European Union, said Zelenskyy, “is going to be much stronger with us. So that’s for sure. Without you, Ukraine is going to be lonesome.

“We have proven our strengths,” he said, closing out his speech. “We have proven that as at a minimum we are exactly the same as you. So do prove that you are with us. Do prove that you will not let us go. Do prove that you indeed are Europeans and then life will win over death and light will win over darkness. Glory be to Ukraine.”

Russians get closer to Kyiv

5:40 a.m. EST March 1

Russian shelling pounded civilian targets in Ukraine’s second-largest city again Tuesday and a 40-mile convoy of tanks and other vehicles threatened the capital — tactics Ukraine’s embattled president said were designed to force him into concessions in Europe’s largest ground war in generations.

With the Kremlin increasingly isolated by tough economic sanctions that have tanked the ruble currency, Russian troops attempted to advance on Ukraine’s two biggest cities. In strategic Kharkiv, an eastern city with a population of about 1.5 million, videos posted online showed explosions hitting the region’s Soviet-era administrative building and residential areas.

Throughout the country, many Ukrainian civilians spent another night huddled in shelters, basements or corridors.

The casualty toll mounted as Ukraine faced Day 6 of a Russian invasion that has shaken the 21st century world order. Hopes for a negotiated solution to the war dimmed after a first, five-hour session of talks between Ukraine and Russia yielded no stop in the fighting, though both sides agreed to another meeting in coming days.

With Western powers sending weapons to Ukraine and driving a global squeeze of Russia’s economy, President Vladimir Putin’s options diminished as he seeks to redraw the global map — and pull Ukraine’s western-leaning democracy back into Moscow’s orbit.

“I believe Russia is trying to put pressure (on Ukraine) with this simple method,” Ukrainian President Volodymyr Zelenskyy said late Monday in a video address, referring to stepped-up shelling. He did not offer details of the talks between Ukrainian and Russian envoys, but he said Kyiv was not prepared to make concessions “when one side is hitting another with rocket artillery.”

As the talks along the Belarusian border wrapped up, several blasts could be heard in the capital, and Russian troops advanced on the city of nearly 3 million. The convoy of armored vehicles, tanks, artillery and support vehicles was 25 kilometers (17 miles) from the center of the city and stretched about 65 kilometers (40 miles), according to satellite imagery from Maxar Technologies.

“They want to break our nationhood, that’s why the capital is constantly under threat,” Zelenskyy said, saying that it was hit by three missile strikes on Monday and that hundreds of saboteurs were roaming the city.

Kharkiv, near the Russian border, is another key target. One after the other, explosions burst through a residential area of the city in one video verified by AP. In the background, a man pleaded with a woman to leave, and a woman cried.

Determined for life to go on despite the shelling, hospital workers transferred a Kharkiv maternity ward to a bomb shelter. Amid makeshift electrical sockets and mattresses piled up against the walls, pregnant women paced the crowded space, accompanied by the cries of dozens of newborns.

The Russian military has denied targeting residential areas despite abundant evidence documented by AP reporters around Ukraine of shelling of homes, schools and hospitals.

Regional administration chief Oleh Sinehubov said that the administration headquarters in the city center also came under Russian shelling. Images posted online showed the building’s facade and interior badly damaged by a powerful explosion that also blew up part of its roof. The state emergencies agency said that attack wounded six people, including a child.

Sinehubov said that at least 11 people were killed and scores of others were wounded during Monday’s shelling of the city.

Meanwhile, flames shot up from a military base northeast of Kyiv, in the suburb of Brovary, in footage shot from a car driving past. In another video verified by AP, a passenger pleads with the driver, “Misha, we need to drive quickly as they’ll strike again.”

And Ukrainian authorities released details and photos of an attack Sunday on a military base in Okhtyrka, a city between Kharkiv and Kyiv, saying more than 70 Ukrainian soldiers were killed along with some local residents. The attack could not be immediately confirmed.

The Russian military’s movements have been stalled by fierce resistance on the ground and a surprising inability to dominate Ukraine’s airspace.

In the face of that resistance, the Kremlin has twice in as many days raised the specter of nuclear war and put on high alert an arsenal that includes intercontinental ballistic missiles and long-range bombers. Stepping up his rhetoric, President Vladimir Putin denounced the United States and its allies as an “empire of lies.”

Western nations have increased weapons shipments to Ukraine to help its forces defend themselves — but have so far ruled out sending in troops. Still, the embattled country moved to solidify its ties to the West by applying to join the European Union — a largely symbolic move for now, but one that won’t sit well with Putin, who was already infuriated by Ukraine’s desire to join the NATO alliance.

Messages aimed at the advancing Russian soldiers popped up on billboards, bus stops and electronic traffic signs across the capital. Some used profanity to encourage Russians to leave. Others appealed to their humanity.

“Russian soldier — Stop! Remember your family. Go home with a clean conscience,” one read.

Fighting raged in other towns and cities. The strategic port city of Mariupol, on the Sea of Azov, is “hanging on,” said Zelenskyy adviser Oleksiy Arestovich. An oil depot was reported bombed in the eastern city of Sumy.

Isachenkov reported from Moscow, and Miller from Washington. Francesca Ebel, Josef Federman and Andrew Drake in Kyiv; Mstyslav Chernov and Nic Dumitrache in Mariupol, Ukraine; and other AP journalists from around the world contributed to this report.

Hundreds of casualties were reported in the fighting, which included shelling that sliced through a Kyiv apartment building and pummeled bridges and schools. There also were growing signs that Russia may be seeking to overthrow Ukraine’s government, which U.S. officials have described as Russian President Vladimir Putin’s ultimate objective.

The assault represented Putin’s boldest effort yet to redraw the world map and revive Moscow’s Cold War-era influence. It triggered new international efforts to end the invasion, including direct sanctions on Putin.

As his country confronted explosions and gunfire, and as the fate of Kyiv hung in the balance, Ukraine President Volodymyr Zelenskyy appealed for a cease-fire and warned in a bleak statement that multiple cities were under attack.

“This night we have to stand firm,” he said. “The fate of Ukraine is being decided right now.”

Zelenskyy was urged to evacuate Kyiv at the behest of the U.S. government but turned down the offer, according to a senior American intelligence official with direct knowledge of the conversation. The official quoted the president as saying that “the fight is here” and that he needed anti-tank ammunition but “not a ride.”

For their part, U.S. defense officials believe the Russian offensive has encountered considerable resistance and is proceeding slower than Moscow had envisioned, though that could change quickly.

The Kremlin accepted Kyiv’s offer to hold talks, but it appeared to be an effort to squeeze concessions out of the embattled Zelenskyy instead of a gesture toward a diplomatic solution.

The Russian military continued its advance, laying claim Friday to the southern Ukraine city of Melitopol. Still, it was unclear in the fog of war how much of Ukraine is still under Ukrainian control and how much or little Russian forces have seized.

As fighting persisted, Ukraine’s military reported shooting down an II-76 Russian transport plane carrying paratroopers near Vasylkiv, a city 25 miles (40 kilometers) south of Kyiv, an account confirmed by a senior American intelligence official. It was unclear how many were on board. Transport planes can carry up to 125 paratroopers.

The U.S. and other global powers slapped ever-tougher sanctions on Russia as the invasion reverberated through the world’s economy and energy supplies, threatening to further hit ordinary households. U.N. officials said millions could flee Ukraine. Sports leagues moved to punish Russia and even the popular Eurovision song contest banned it from the May finals in Italy.

Through it all, Russia remained unbowed, vetoing a U.N. Security Council resolution demanding that it stop attacking Ukraine and withdraw troops immediately. The veto was expected, but the U.S. and its supporters argued that the effort would highlight Moscow’s international isolation. The 11-1 vote, with China, India and the United Arab Emirates abstaining, showed significant but not total opposition to Russia’s invasion of its smaller, militarily weaker neighbor.

The meeting exposed Russia-Ukraine frictions, including when Ukrainian Ambassador Sergiy Kyslytsya requested a moment of silence to pray for those killed and asked Russian Ambassador Vassily Nebenzia to pray “for salvation.” Nebenzia retorted that the remembrance should include people who have died in eastern Ukraine’s Donbas region. Pro-Russian separatists there have been fighting the Ukrainian government, which Russia accuses of abuses. A moment of tense silence did ensue.

NATO, meanwhile, decided to send parts of the alliance’s response force to help protect its member nations in the east for the first time. NATO did not say how many troops would be deployed but added that it would involve land, sea and air power.

Day Two of Russia’s invasion, the largest ground war in Europe since World War II, focused on the Ukrainian capital, where Associated Press reporters heard explosions starting before dawn. Gunfire was reported in several areas.

A large boom was heard in the evening near Maidan Nezalezhnosti, the square in central Kyiv that was the heart of protests which led to the 2014 ouster of a Kremlin-friendly president. The cause was not immediately known.

Five explosions struck near a major power plant on Kyiv’s eastern outskirts, said Mayor Vitaly Klitschko. There was no information on what caused them, and no electrical outages were immediately reported.

It was unclear how many people overall had died. Ukrainian officials reported at least 137 deaths on their side from the first full day of fighting and claimed hundreds on the Russian one. Russian authorities released no casualty figures.

U.N. officials reported 25 civilian deaths, mostly from shelling and airstrikes, and said that 100,000 people were believed to have left their homes. They estimate that up to 4 million could flee if the fighting escalates.

Zelenskyy tweeted that he and U.S. President Joe Biden spoke by phone and discussed “strengthening sanctions, concrete defense assistance and an antiwar coalition.”

His whereabouts were kept secret after Zelenskyy told European leaders in a call Thursday that he was Russia’s No. 1 target — and that they might not see him again alive. His office later released a video of him standing with senior aides outside the presidential office and saying that he and other government officials would stay in the capital.

Zelenskyy earlier offered to negotiate on a key Putin demand: that Ukraine declare itself neutral and abandon its ambition of joining NATO. The Kremlin said Kyiv initially agreed to have talks in Minsk, then said it would prefer Warsaw and later halted communications. Foreign Ministry spokeswoman Maria Zakharova said later that Kyiv would discuss prospects for talks on Saturday.

The assault was anticipated for weeks by the U.S. and Western allies and denied to be in the works just as long by Putin. He argued the West left him with no other choice by refusing to negotiate Russia’s security demands.

In a window into how the increasingly isolated Putin views Ukraine and its leadership, he urged Ukraine’s military to surrender, saying: “We would find it easier to agree with you than with that gang of drug addicts and neo-Nazis who have holed up in Kyiv and have taken the entire Ukrainian people hostage.”

Playing on Russian nostalgia for World War II heroism, the Kremlin equates members of Ukrainian right-wing groups with neo-Nazis. Zelenskyy, who is Jewish, angrily dismisses those claims.

Putin has not disclosed his ultimate plans for Ukraine. Foreign Minister Sergey Lavrov gave a hint, saying, “We want to allow the Ukrainian people to determine its own fate.” Putin spokesman Dmitry Peskov said Russia recognizes Zelenskyy as the president, but would not say how long the Russian military operation could last.

Ukrainians abruptly adjusted to life under fire, after Russian forces invaded the country from three sides as they massed an estimated 150,000 troops nearby.

Residents of a Kyiv apartment building woke to screaming, smoke and flying dust. What the mayor identified as Russian shelling tore off part of the building and ignited a fire.

“What are you doing? What is this?” resident Yurii Zhyhanov asked Russian forces. Like countless other Ukrainians, he grabbed what belongings he could, took his mother, and fled, car alarms wailing behind him.

Elsewhere in Kyiv, the body of a dead soldier lay near an underpass. Fragments of a downed aircraft smoked amid the brick homes of a residential area. Black plastic was draped over body parts found beside them. People climbed out of bomb shelters, basements and subways to face another day of upheaval.

“We’re all scared and worried. We don’t know what to do then, what’s going to happen in a few days,” said Lucy Vashaka, 20, a worker at a small Kyiv hotel.

At the Pentagon, press secretary John Kirby said the U.S. believes the offensive, including its advance on Kiev, has gone more slowly than Moscow had planned, noting that Ukraine forces have been fighting back. But he also said the military campaign is in an early stage and circumstances can change rapidly.

The Biden administration said Friday that it would move to freeze the assets of Putin and Lavrov, following the European Union and Britain in directly sanctioning top Russian leadership.

Zakharova, the Russian Foreign Ministry spokeswoman, called the sanctions against Putin and Lavrov “an example and a demonstration of a total helplessness” of the West.

Isachenkov and Litvinova reported from Moscow. Francesca Ebel, Josef Federman and Andrew Drake in Kyiv; Angela Charlton in Paris; Geir Moulson and Frank Jordans in Berlin; Raf Casert and Lorne Cook in Brussels; Nic Dumitrache in Mariupol, Ukraine; Matt Sedensky in New York; Jennifer Peltz at the United Nations; James LaPorta in Boca Raton, Fla., and Robert Burns, Matthew Lee, Aamer Madhani, Eric Tucker, Nomaan Merchant, Ellen Knickmeyer, Zeke Miller, Chris Megerian and Darlene Superville in Washington contributed.

A fog of war remained over the country as the American East Coast awoke Thursday morning, and conflicting reports sprouted on social media regarding fighting at various locations. Ukraine’s leadership said at least 40 people have been killed so far in what it called a “full-scale war” targeting the country from the east, north and south.

But as morning broke in Ukraine, big explosions were heard in the capital Kyiv, as well as Kharkiv and Odesa as world leaders decried the start of an invasion that could lead to massive deaths, a toppling of Ukraine’s democratically elected government and a threat to Europe’s post-Cold War balance.

A Ukrainian presidential adviser said that Russian forces have launched an attack on Ukraine from the north, east and south. The adviser, Mykhailo Podolyak, said “the Ukrainian military is fighting hard.”

Podolyak said Thursday that “our army is fighting back inflicting significant losses to the enemy.” He said that there have been civilian casualties, but didn’t give details.

He said that “Ukraine now needs a greater and very specific support from the world — military-technical, financial as well as tough sanctions against Russia,” he said.

Ukraine’s leadership said at least 40 people have been killed so far in what it called a “full-scale war” targeting the country from the east, north and south.

Ukrainian border guards released footage of what they said were Russian military vehicles moving in, and big explosions were heard in the capital Kyiv, Kharkiv in the east and Odesa in the west. As the Russian military claimed to have wiped out Ukraine’s entire air defenses in a matter of hours, Ukrainians fled some cities and European authorities declared Ukrainian air space an active conflict zone.

‘All-out defense mode’

Meanwhile, Ukraine’s defense minster, Oleksiy Reznikov, called on citizens looking to fight the Russians to enroll with the country’s territorial defense units, The New York Times reported.

“The enemy is attacking, but our army is indestructible,” he said. “Ukraine is moving into all-out defense mode.”

Ukrainians have started fleeing some cities and the Russian military claimed it had taken out all of the country’s air defenses and air bases within hours of the invasion’s commencement.

Security camera footage showed a line of Russian military vehicles crossing into Ukraine from Crimea, which Russia annexed in 2014.

Ukrainian President Volodymyr Zelenskyy declared martial law and said Russia was targeting the country’s military infrastructure.

Zelenskyy cut diplomatic ties with Moscow and declared martial law, saying Russia has targeted Ukraine’s military infrastructure. Ukrainians who had long braced for the prospect of an assault were urged to stay home and not to panic even as Ukrainian authorities reported artillery barrages and airstrikes on targets around the country.

An adviser to Ukraine’s president, Oleksii Arestovich, said about 40 people have been killed so far in the Russian attack and several dozen wounded. He didn’t specify whether the casualties included civilians.

“The Ukrainian military is waging hard battles, repelling attacks in Donbas and other regions in the east, north and south,” Zelenskyy said at a briefing. He said the Ukrainian authorities will hand weapons to all those willing to defend the country.

Citizens were urged to stay home and not panic, even as the country’s border guard agency reported an artillery barrage by Russian troops from neighboring Belarus.

The world reacts

President Joe Biden has pledged tough sanctions to punish Russia, even as Putin asserted in a televised address before the invasion that the attack was meant to protect civilians in eastern Ukraine — a false claim the U.S. had predicted he would make to justify the military actions.

Japan, Italy, Spain, Australia and France all condemned the attack Thursday, and Latvia called for an invocation of NATO’s Article 4, which allows for any member to call a group consultation when they think “the territorial integrity, political independence or security of any of the parties is threatened.”

If Russia takes the entirety of Ukraine, it would immediately abut several NATO member states.

NATO chief Jens Stoltenberg has convened a meeting of NATO ambassadors to assess the invasion of Ukraine.

The meeting Thursday morning will “address the situation in Ukraine and the consequences of Russia’s unprovoked attack.”

Earlier, Stoltenberg had already condemned Russia’s invasion. “Despite our repeated warnings and tireless efforts to engage in diplomacy, Russia has chosen the path of aggression,” Stoltenberg said.

He also warned Moscow that the alliance will “do all it takes to protect and defend” NATO members.

He called the invasion a “grave breach of international law, and a serious threat to Euro-Atlantic security. I call on Russia to cease its military action immediately.”

The European Union is planning the “strongest, the harshest package” of sanctions it has ever considered at an emergency summit Thursday.

European Commission President Ursula von der Leyen said that “the target is the stability in Europe and the whole of the international peace order, and we will hold President (Vladimir) Putin accountable for that.”

“We will present a package of massive and targeted sanctions to European leaders for approval,” she said.

EU foreign policy chief Josep Borrell called it the “strongest, the harshest package” ever considered.

“A major nuclear power has attacked a neighbor country and is threatening reprisals of any other states that may come to the rescue,” Borrell said. “This is not only the greatest violation of international law, it’s a violation of the basic principles of human co-existence. It’s costing many lives with unknown consequences ahead of us. The European Union will respond in the strongest possible terms.”

Putin defiant

Putin accuses the United States and its allies of ignoring Russia’s demands to prevent Ukraine from joining NATO and other security guarantees.

He also claimed that Russia does not intend to occupy Ukraine but will move to “demilitarize” it and bring those who committed crimes to justice.

But as the attack commenced, some analysts questioned Putin’s claim that the Russian military would hold back.

Appearing on CNN, retired Army Gen. Wesley Clark urged Ukrainian’s outmatched forces to consolidate in cities before the Russians arrived.

“They’re certainly going to need support, and the West needs to give them that support,” said Clark, who served as NATO Supreme Allied Commander from 1997 to 2000.

In a written statement Wednesday night in the United States, Biden condemned the “unprovoked and unjustified attack” and promised that the United States and its allies would “hold Russia accountable.”

Biden is slated to speak to Americans Thursday following a meeting of the Group of Seven leaders and more sanctions against Russia are expected to be announced Thursday as well.

Ukraine’s Foreign Minister Dmytro Kuleba described the assault as a “full-scale invasion” and said Ukraine will “defend itself and will win. The world can and must stop Putin. The time to act is now.”

In the capital, Kyiv Mayor Vitaly Klitschko advised residents to stay home unless they are involved in critical work and urged them to prepare go-bags with necessities and documents if they need to evacuate.

‘What could be worse?’

An Associated Press photographer in Mariupol reported hearing explosions and seeing dozens of people with suitcases heading for their cars to leave the city.

“We are facing a war and horror. What could be worse?” 64-year-old Liudmila Gireyeva said in Kyiv. She planned to head to the western city of Lviv and then to try to move to Poland to join her daughter.

Putin “will be damned by history, and Ukrainians are damning him,” she said.

Russian claims about knocking out Ukrainian air defenses and Ukrainian claims to have shot down several Russian aircraft could not immediately be verified.

The Ukrainian air defense system and air force date back to the Soviet era and are dwarfed by Russia’s massive air power and its inventory of precision weapons.

The Russian Defense Ministry said it was not targeting cities, but using precision weapons and claimed that “there is no threat to civilian population.”

Anton Gerashchenko, an adviser to Ukraine’s interior minister, said on Facebook that the Russian military had launched missile strikes on Ukrainian military command facilities, air bases and military depots in Kyiv, Kharkiv and Dnipro.

After the initial explosions in Kyiv, people could be heard shouting in the streets. Then a sense of normality returned, with cars circulating and people walking in the streets as a pre-dawn commute appeared to start in relative calm.

Later in the day, photos emerged of lines forming outside Kyiv grocery stores.

Markets shudder

The consequences of the conflict and resulting sanctions on Russia could reverberate throughout the world, upending geopolitical dynamics in Europe as well as affecting energy supplies in Europe and jolting global financial markets.

Asian stock markets plunged and oil prices surged as the attack began. Earlier, Wall Street’s benchmark S&P 500 index fell 1.8% to an eight-month low after the Kremlin said rebels in eastern Ukraine asked for military assistance.

Anticipating international condemnation and countermeasures, Putin issued a stark warning to other countries not to meddle.

“Whoever tries to impede us, let alone create threats for our country and its people, must know that the Russian response will be immediate and lead to the consequences you have never seen in history,” he said.

Putin urged Ukrainian servicemen to “immediately put down arms and go home.”

Nuclear threats

In a stark reminder of Russia’s nuclear power, Putin warned that “no one should have any doubts that a direct attack on our country will lead to the destruction and horrible consequences for any potential aggressor.” He emphasized that Russia is “one of the most potent nuclear powers and also has a certain edge in a range of state-of-the-art weapons.”

Though the U.S. on Tuesday announced the repositioning of forces around the Baltics, Biden has said he will not send in troops to fight Russia.

Putin announced the military operation after the Kremlin said rebels in eastern Ukraine asked Russia for military assistance to help fend off Ukrainian “aggression,” an announcement that the White House said was a “false flag” operation by Moscow to offer up a pretext for an invasion.

Putin’s announcement came just hours after the Ukrainian president rejected Moscow’s claims that his country poses a threat to Russia and made a passionate, last-minute plea for peace.

“The people of Ukraine and the government of Ukraine want peace,” Zelenskyy said in an emotional overnight address, speaking in Russian in a direct appeal to Russian citizens. “But if we come under attack, if we face an attempt to take away our country, our freedom, our lives and lives of our children, we will defend ourselves. When you attack us, you will see our faces, not our backs.”

Zelenskyy said he asked to arrange a call with Putin late Wednesday, but the Kremlin did not respond.

In an apparent reference to Putin’s move to authorize the deployment of the Russian military to “maintain peace” in eastern Ukraine, Zelenskyy warned that “this step could mark the start of a big war on the European continent.”

“Any provocation, any spark could trigger a blaze that will destroy everything,” he said.

He challenged the Russian propaganda claims, saying that “you are told that this blaze will bring freedom to the people of Ukraine, but the Ukrainian people are free.”

At an emergency meeting of the U.N. Security Council called by Ukraine because of the imminent threat of a Russian invasion, members still unaware of Putin’s announcement appealed to him to stop an attack.

U.N. Secretary-General Antonio Guterres opened the meeting, just before the announcement, telling Putin: “Stop your troops from attacking Ukraine. Give peace a chance. Too many people have already died.”

Even before Putin’s announcement, dozens of nations imposed sanctions on Russia, further squeezing Russian oligarchs and banks out of international markets.

The Russian Foreign Ministry has shrugged off the sanctions, saying that “Russia has proven that, with all the costs of the sanctions, it is able to minimize the damage.”

The threat of war has already shredded Ukraine’s economy and raised the specter of massive casualties, energy shortages across Europe and global economic chaos.

Karmanau and Heintz reported from Kyiv. Angela Charlton in Paris; Frank Jordans in Berlin; Lorne Cook in Brussels, Frank Bajak in Boston, Robert Burns, Matthew Lee, Aamer Madhani, Eric Tucker, Ellen Knickmeyer, Zeke Miller, Chris Megerian and Darlene Superville in Washington contributed.

Russian troops launched their anticipated attack on Ukraine on Thursday, as President Vladimir Putin cast aside international condemnation and sanctions, warning other countries that any attempt to interfere would lead to “consequences you have never seen.”

Big explosions were heard before dawn in Kyiv, Kharkiv and Odessa as world leaders decried the start of a Russian invasion that could cause massive casualties and topple Ukraine’s democratically elected government.

Ukraine’s border guard agency reported that the Russian military attacked the country from neighboring Belarus.

The agency said the Russian troops unleashed artillery barrage as part of an attack backed by Belarus. They said the Ukrainian border guards were firing back, adding that there was no immediate report of casualties.

Russian troops had deployed to its ally Belarus for military drills, a move that the West saw as a prelude to an invasion of Ukraine. The Ukrainian capital of Kyiv is about 75 kilometers (50 miles) south of the border with Belarus.

As the morning proceeded in Ukraine, the Russian military said it had knocked out Ukraine’s air defense assets and airbases.

The Russian Defense Ministry said the Russian strikes have “suppressed air defense means of the Ukrainian military,” adding that the infrastructure of Ukraine’s military bases has been incapacitated.” It denied the claims that a Russian warplane was shot down over Ukraine.

The Ukrainian military, meanwhile, reported that it has shot down five Russian aircraft while fending off the Russian attack on the country.

The websites of Ukraine’s defense, foreign and interior ministries were unreachable or painfully slow to load Thursday morning after a punishing wave of distributed-denial-of-service attacks as Russia struck at its neighbor, explosions shaking the capital of Kyiv and other major cities.

In addition to DDoS attacks on Wednesday, cybersecurity researchers said unidentified attackers had infected hundreds of computers with destructive malware, some in neighboring Latvia and Lithuania.

U.S. President Joe Biden pledged new sanctions meant to punish Russia for an act of aggression that the international community had for weeks anticipated but could not prevent through diplomacy.

Putin justified it all in a televised address, asserting the attack was needed to protect civilians in eastern Ukraine — a false claim the U.S. had predicted he would make as a pretext for an invasion. He accused the U.S. and its allies of ignoring Russia’s demand to prevent Ukraine from joining NATO and offer Moscow security guarantees, and credulously claimed that Russia doesn’t intend to occupy Ukraine but will move to “demilitarize” it and bring those who committed crimes to justice.

In a written statement Wednesday night, President Joe Biden said Russian President Vladimir Putin would be held accountable for “catastrophic loss of life and human suffering.”

“The prayers of the entire world are with the people of Ukraine as they suffer an unprovoked and unjustified attack by Russian military forces,” Biden said in his message.

“President Putin has chosen a premeditated war that will bring a catastrophic loss of life and human suffering,” said Biden. “Russia alone is responsible for the death and destruction this attack will bring, and the United States and its Allies and partners will respond in a united and decisive way.

“The world will hold Russia accountable,” he said. “I will be monitoring the situation from the White House this evening and will continue to get regular updates from my national security team.”

Biden said that he would meet Thursday “with my G7 counterparts in the morning and then speak to the American people to announce the further consequences the United States and our Allies and partners will impose on Russia for this needless act of aggression against Ukraine and global peace and security. We will also coordinate with our NATO Allies to ensure a strong, united response that deters any aggression against the Alliance. Tonight, Jill and I are praying for the brave and proud people of Ukraine.”

The Pentagon declined comment Wednesday night after the attacks began, deferring to statements press secretary John Kirby made at an earlier briefing.

“We believe that they are now at a state of readiness where they could attack at any time,” Kirby said of the more than 150,000 Russian troops amassed around Ukraine.

The United Nations Security Council quickly scheduled an emergency meeting Wednesday night at Ukraine’s request.

During the meeting, U.N. Secretary-General Antonio Guterres urgently appealed to Putin: “in the name of humanity, bring your troops back to Russia.”

But during that meeting, Putin announced he was launching a “special military operation” into eastern Ukraine.

Guterres later urged the Russian president to withdraw his troops and added: “In the name of humanity do not allow to start in Europe what could be the worst war since the beginning of the century, with consequences not only devastating for Ukraine, not only tragic for the Russian Federation, but with an impact we cannot even foresee in relation to the consequences for the global economy.”

As Russian troops attacked Ukraine, world leaders reacted Thursday with outrage — one called it “an unjustified barbarian act” — and vowed to both tighten sanctions and hold the Kremlin accountable.

The turmoil from the beginning of a long-feared act of aggression rippled from Europe to Asia. Stock markets plunged, oil prices surged, and European aviation officials warned of a high risk to civilian aircraft over Ukraine, reminding air operators that “this is now an active conflict zone.”

As the Russian offensive continued, but a fog of war left many questions unanswered Thursday, Ukrainian leaders were decidedly defiant despite facing a pronounced military disadvantage.

“Putin has just launched a full-scale invasion of Ukraine,” Ukraine Foreign Minister Dmytro Kuleba said in a tweet. “Peaceful Ukrainian cities are under strikes. This is a war of aggression. Ukraine will defend itself and will win. The world can and must stop Putin. The time to act is now.”

A full-blown Russian invasion could cause massive casualties and topple Ukraine’s democratically elected government. And the consequences of the conflict and resulting sanctions levied on Russia could reverberate throughout the world, affecting energy supplies in Europe, jolting global financial markets and threatening the post-Cold War balance on the continent.

Putin announced the military operation after the Kremlin said rebels in eastern Ukraine asked Russia for military assistance to help fend off Ukrainian “aggression.” The announcement immediately fueled fears that Moscow was offering up a pretext for war, just as the West had warned.

Putin said he had decided to conduct a “special military operation to protect Donbass.”

He called on the Ukrainian military to “immediately lay down their arms and go home” and added that “Russia’s plans do not include the occupation of Ukraine.”

“We will strive for the demilitarization and denazification of Ukraine,” he said.

A short time later, the Ukrainian president, Volodymyr Zelenskyy, rejected Moscow’s claims that his country poses a threat to Russia and said a Russian invasion would cost tens of thousands of lives.

“The people of Ukraine and the government of Ukraine want peace,” President Zelenskyy said in an emotional overnight address, speaking in Russian in a direct appeal to Russian citizens. “But if we come under attack, if we face an attempt to take away our country, our freedom, our lives and lives of our children, we will defend ourselves. When you attack us, you will see our faces, not our backs.”

Zelenskyy said he asked to arrange a call with Russian President Vladimir Putin late Wednesday, but the Kremlin did not respond.

In an apparent reference to Putin’s move to authorize the deployment of the Russian military to “maintain peace” in eastern Ukraine, Zelensky warned that “this step could mark the start of a big war on the European continent.”

“Any provocation, any spark could trigger a blaze that will destroy everything,” he said.

He challenged the Russian propaganda claims, saying that “you are told that this blaze will bring freedom to the people of Ukraine, but the Ukrainian people are free.”

At Wednesday night’s U.N. Security Council meeting, Ukrainian Foreign Minister Dmytro Kuleba called the separatists’ request “a further escalation of the security situation.”

Anxiety about an imminent Russian offensive against its neighbor soared after Putin recognized the separatist regions’ independence on Monday, endorsed the deployment of troops to the rebel territories and received parliamentary approval to use military force outside the country.

Kremlin spokesman Dmitry Peskov said the rebel chiefs wrote to Putin on Wednesday, pleading with him to intervene after Ukrainian shelling caused civilian deaths and crippled vital infrastructure.

White House press secretary Jen Psaki said the separatists’ request for Russian help was an example of the sort of “false-flag” operation that the U.S. and its allies have expected Moscow to use as a pretense for war.

“So we’ll continue to call out what we see as false-flag operations or efforts to spread misinformation about what the actual status is on the ground,” she said.

Earlier Wednesday, Ukrainian lawmakers approved a decree that imposes a nationwide state of emergency for 30 days starting Thursday. The measure allows authorities to declare curfews and other restrictions on movement, block rallies and ban political parties and organizations “in the interests of national security and public order.”

The action reflected increasing concern among Ukrainian authorities after weeks of trying to project calm. The Foreign Ministry advised against travel to Russia and recommended that any Ukrainians who are there leave immediately.

“For a long time, we refrained from declaring a state of emergency … but today the situation has become more complicated,” Ukrainian National Security and Defense Council head Oleksiy Danilov told parliament, emphasizing that Moscow’s efforts to destabilize Ukraine represented the main threat.

Pentagon press secretary Kirby said this week the Russian force of more than 150,000 troops arrayed along Ukraine’s borders is in an advanced state of readiness. “They are ready to go right now,” Kirby said.

The latest images released by the Maxar satellite image company showed Russian troops and military equipment deployed within 10 miles of the Ukrainian border and less than 50 miles from Ukraine’s second-largest city, Kharkiv.

Early Thursday, airspace over all of Ukraine was shut down to civilian air traffic, according to a notice to airmen. A commercial flight tracking website showed that an Israeli El Al Boeing 787 flying from Tel Aviv to Toronto turned abruptly out of Ukrainian airspace before detouring over Romania, Hungary, Slovakia and Poland. The only other aircraft tracked over Ukraine was a U.S. RQ-4B Global Hawk unmanned surveillance plane, which began flying westward early Thursday after Russia put in place flight restrictions over Ukrainian territory.

Another wave of distributed-denial-of-service attacks hit Ukraine’s parliament and other government and banking websites on Wednesday, and cybersecurity researchers said unidentified attackers had also infected hundreds of computers with destructive malware.

Officials have long said they expect cyberattacks to precede and accompany any Russian military incursion, and analysts said the incidents hew to a nearly two-decade-old Russian playbook of wedding cyber operations with real-world aggression.

In other developments, Russia evacuated its embassy in Kyiv; Ukraine recalled its ambassador to Russia and considered breaking all diplomatic ties with Moscow and dozens of nations further squeezed Russian oligarchs and banks out of international markets.

President Joe Biden allowed sanctions to move forward against the company that built the Russia-to-Germany Nord Stream 2 gas pipeline and against the company’s CEO.

“As I have made clear, we will not hesitate to take further steps if Russia continues to escalate,” Biden said in a statement.

Germany said Tuesday that it was indefinitely suspending the project, after Biden charged that Putin had launched “the beginning of a Russian invasion of Ukraine” by sending troops into the separatist regions. The pipeline is complete but has not yet begun operating.

Putin said Tuesday that he had not yet sent any Russian troops into the rebel regions, contrary to Western claims, and Donetsk rebel leader Denis Pushilin insisted Wednesday there were no Russian troops in the region, even though a local council member claimed the previous day they had moved in.

Already, the threat of war has shredded Ukraine’s economy and raised the specter of massive casualties, energy shortages across Europe and global economic chaos.

European Union sanctions against Russia took effect, targeting several companies along with 351 Russian lawmakers who voted for a motion urging Putin to recognize the rebel regions and 27 senior government officials, business executives and top military officers.

The Russian Foreign Ministry has shrugged off the sanctions, saying that “Russia has proven that, with all the costs of the sanctions, it is able to minimize the damage.”

In Ukraine’s east, one Ukrainian soldier was killed and six more wounded after rebel shelling, the Ukrainian military said Wednesday. Separatist officials reported several explosions on their territory overnight and three civilian deaths.

Facing a barrage of criticism at the 193-member United Nations General Assembly, Russia’s U.N. ambassador, Vassily Nebenzia, warned Ukraine that Russia will monitor a cease-fire in the east and emphasized that “no one intends to go softly, softly with any violators.”

“A new military adventure” by Kyiv “might cost the whole of Ukraine very dearly,” he warned ominously.

After weeks of rising tensions, Putin’s steps this week dramatically raised the stakes. He recognized the independence of the separatist regions, a move he said extends even to the large parts of the territories now held by Ukrainian forces, and had parliament grant him authority to use military force outside the country.

Putin laid out three conditions that he said could end the standoff, urging Kyiv to renounce its bid to join NATO, to partially demilitarize and to recognize Russia’s sovereignty over Crimea, the Black Sea peninsula that Moscow annexed from Ukraine in 2014. Ukraine long has rejected such demands.

Litvinova reported from Moscow. Angela Charlton in Paris; Frank Jordans in Berlin; Lorne Cook in Brussels, Vladimir Isachenkov in Moscow, Frank Bajak in Boston, Robert Burns, Matthew Lee, Aamer Madhani, Eric Tucker, Ellen Knickmeyer, Zeke Miller, Chris Megerian and Darlene Superville in Washington contributed.

Russia’s action extends what it said were military exercises, originally set to end Sunday, that brought a sizable contingent of Russian forces to Belarus, Ukraine’s neighbor to the north. The presence of the Russian troops raised concern that they could be used to sweep down on the Ukrainian capital, Kyiv, a city of about 3 million people less than a three-hour drive away.

U.S. President Joe Biden convened the National Security Council at the White House on Russia’s military buildup around Ukraine. White House officials released no immediate details of their two-hour discussion.

Western leaders intensified warnings that Russia was poised to attack its neighbor, which is surrounded on three sides by at least 150,000 Russian soldiers, warplanes and equipment.

Russia held nuclear drills Saturday as well as the conventional exercises in Belarus, and has ongoing naval drills off the coast in the Black Sea.

The United States and many European countries have charged for months that Russia is trying to create pretexts to invade. They have threatened massive, immediate sanctions if it does.

“We’re talking about the potential for war in Europe,” U.S. Vice President Kamala Harris said Sunday at a security conference in Munich, Germany. “It’s been over 70 years, and through those 70 years … there has been peace and security.”

A top European Union official, Charles Michel, said: “The big question remains: Does the Kremlin want dialogue?”

“We cannot forever offer an olive branch while Russia conducts missile tests and continues to amass troops,” said Michel, the president of the European Council.

Ukrainian President Volodymyr Zelenskyy called Saturday on Russian President Vladimir Putin to choose a place where the two leaders could meet to try to resolve the crisis and on Sunday appealed for a cease-fire on Twitter. Russia has denied plans to invade, but the Kremlin did not respond to Zelenskyy’s offer to meet. It was Belarus — not Russia — that announced the extension of the drills.

NATO has estimated there are 30,000 Russian troops in Belarus.

After a call with French President Emmanuel Macron, Putin blamed Ukraine for the escalation at the contact line and NATO for “pumping modern weapons and ammunition” into Ukraine. The Kremlin statement mentioned a cease-fire only in passing and made no mention of Zelenskyy’s call for a meeting.

In Kyiv, life continued seemingly as usual on a mild winter Sunday, with brunches and church services. Katerina Spanchak, who fled the separatist-occupied Lugansk region years ago, said she prayed for peace.

“We all love life, and we are all united by our love of life. We should appreciate it every day. That’s why I think everything will be fine,” Spanchak said outside services at St. Michael’s monastery.

But in Lugansk, the area of eastern Ukraine where her parents still live, and neighboring Donetsk, separatist leaders ordered a full military mobilization and sent more civilians to Russia, which has issued about 700,000 passports to residents of the rebel-held territories. Claims that Russian citizens are being endangered might be used as justification for military action.

Officials in the separatist territories claimed Ukrainian forces launched several artillery attacks over the past day and that two civilians were killed during an unsuccessful assault on a village near the Russian border. Ukraine’s military said two soldiers died in firing from the separatist side on Saturday.

Ukraine’s leader criticized the U.S. and other Western nations for holding back on new sanctions for Russia. Zelenskyy, in comments before the conference, also questioned the West’s refusal to allow Ukraine to join NATO immediately. Putin has demanded that NATO reject Ukraine as a member.

U.S. President Joe Biden said late Friday that based on the latest American intelligence, he was now “convinced” that Putin has decided to invade Ukraine in coming days and assault the capital.

A U.S. military official said an estimated 40% to 50% of the ground forces surrounding Ukraine had moved into attack positions closer to the border. The official, who spoke on condition of anonymity to discuss internal U.S. assessments, said the change had been underway for about a week and did not necessarily mean Putin was committed to an invasion.

Lines of communication between Moscow and the West remain open: Macron spoke with Putin on Sunday for nearly two hours before a 30-minute call with the Ukrainian president. U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov agreed to meet next week.

Blinken said Sunday the U.S. was still working every lever possible to try to dissuade Putin from invading Ukraine but said recent events, including the extension of the troops in Belarus and the increase in shelling along the contact line, showed Putin well underway in laying the pretexts and groundwork for invasion, in line with findings of U.S. intelligence and previous Russian territorial grabs. “So all of this, along with the false flag operations we’ve seen unfold over the weekend, tells us the playbook…is moving forward,” the U.S. secretary of state told CNN.

“Up to the last minute, there is still an option for him to pull back,” Blinken told NBC’s Meet the Press. He said his offer to meet Lavrov in Europe in the coming days was conditioned on Russia not rolling into Ukraine beforehand.

Macron’s office said both the Ukrainian and Russian leaders had agreed to work toward a diplomatic solution “in coming days and coming weeks.”

Immediate worries focused on eastern Ukraine, where Ukrainian forces have been fighting the pro-Russia rebels since 2014 in a conflict that has killed some 14,000 people.

Ukraine and the separatist leaders traded accusations of escalation. Russia on Saturday said at least two shells fired from a government-held part of eastern Ukraine landed across the border, but Ukraine’s foreign minister dismissed that as “a fake statement.”

“When tension is escalated to the maximum, as it is now, for example, on the line of contact, then any spark, any unplanned incident or any minor planned provocation can lead to irreparable consequences,” Putin’ spokesman Dmitry Peskov said in an interview that aired Sunday on Russian state television.

On the front lines, Ukrainian soldiers said they were under orders not to return fire. Zahar Leshushun, peering into the distance with a periscope, had followed the news all day from a trench where he is posted near the town of Zolote.

“Right now, we don’t respond to their fire because …” the soldier said before being interrupted by the sound of an incoming shell. “Oh! They are shooting at us now. They are aiming at the command post.”

Sporadic violence has broken out for years along the line separating Ukrainian forces from the Russia-backed separatists, but the spike in recent days is orders of magnitude higher than anything recently recorded by international monitors: nearly 1,500 explosions in 24 hours.

Denis Pushilin, the head of the pro-Russia separatist government in Ukraine’s Donetsk region, cited an “immediate threat of aggression” from Ukrainian forces in his announcement of a call to arms. Ukrainian officials vehemently denied having plans to take rebel-controlled areas by force.

A similar statement followed from his counterpart in the Luhansk region. On Friday, the rebels began evacuating civilians to Russia with an announcement that appeared to be part of efforts to paint Ukraine as the aggressor.

Heintz reported from Moscow. Mstyslav Chernov in Zolote, Ukraine, Geir Moulson in Berlin, Aamer Madhani in Munich, Ellen Knickmeyer, Robert Burns and Darlene Superville in Washington, Liudas Dapkus in Vilnius, Lithuania, and Yuras Karmanau in Kyiv contributed to this story.

The exercises, originally set to end Sunday, brought a sizable contingent of Russian forces to neighboring Belarus, which borders Ukraine to the north. The presence of the Russian troops raised concern that they could be used to sweep down on the Ukrainian capital, Kyiv.

The announcement came from the defense minister of Belarus, who said the two countries would “continue testing the response forces.”

Early Sunday morning, a Ukrainian military official told Military Times he believed that Russian forces were now fully ready to launch a major attack, concuring with what U.S. officials have been saying. Defense Secretary Lloyd Austin said on Saturday that Russian forces “are uncoiling and are now poised to strike” Ukraine.

Western leaders warned that Russia was poised to attack its neighbor, which is surrounded on three sides by about 150,000 Russian soldiers, warplanes and equipment. Russia held nuclear drills Saturday as well as the conventional exercises in Belarus, and has ongoing naval drills off the coast in the Black Sea.

The United States and many European countries have alleged for months that Russia is trying to create pretexts to invade. They have threatened massive, immediate sanctions if it does.

A top European Union official, Charles Michel, said Sunday that “the big question remains: does the Kremlin want dialogue?”

“We cannot forever offer an olive branch while Russia conducts missile tests and continues to amass troops,” Michel, the president of the European Council, said at the Munich Security Conference. He said, “One thing is certain: if there is further military aggression, we will react with massive sanctions.”

Ukrainian President Volodymyr Zelenskyy called on Russian President Vladimir Putin to choose a place where the two leaders could meet to try to resolve the crisis. Russia has denied plans to invade.

“Ukraine will continue to follow only the diplomatic path for the sake of a peaceful settlement,” Zelenskyy said Saturday at an international security conference in Munich, Germany. There was no immediate response from the Kremlin.

Separatist leaders in eastern Ukraine on Saturday ordered a full military mobilization and sent more civilians to Russia, which has issued about 700,000 passports to residents of the rebel-held territories. Claims that Russian citizens are being endangered might be used as justification for military action.

Officials in the separatist territories claimed Ukrainian forces launched several artillery attacks over the past day and that two civilians were killed in an unsuccessful assault on a village near the Russian border.

U.S. Vice President Kamala Harris on Sunday emphasized the significance of the moment that Europe faces.

“We’re talking about the potential for war in Europe,” Harris said at the Munich Security Conference. “It’s been over 70 years, and through those 70 years … there has been peace and security.”

Ukraine’s leader criticized the U.S. and other Western nations for holding back on new sanctions for Russia. Zelenskyy, in comments before the conference, also questioned the West’s refusal to allow Ukraine to join NATO immediately.

Putin has demanded that NATO not take Ukraine as a member. Harris stood by the U.S. decision to hold off on sanctions but said she wouldn’t second guess Zelenskyy’s “desires for his country.”

In new signs of fears that a war could start within days, Germany and Austria told their citizens to leave Ukraine. German air carrier Lufthansa canceled flights to the capital, Kyiv, and to Odesa, a Black Sea port that could be a key target in an invasion.

NATO’s liaison office in Kyiv said it was relocating staff to Brussels and to the western Ukraine city of Lviv.

U.S. President Joe Biden said late Friday that based on the latest American intelligence, he was now “convinced” that Putin has decided to invade Ukraine in coming days and assault the capital.

A U.S. military official said an estimated 40% to 50% of those ground forces have moved into attack positions closer to the border. The official, who spoke on condition of anonymity to discuss internal U.S. assessments, said the change has been underway for about a week and does not necessarily mean Putin has settled on an invasion.

Lines of communication between Moscow and the West remain open: the American and Russian defense chiefs spoke Friday. French President Emmanuel Macron spoke with Putin on Sunday for nearly two hours before a call with the Ukrainian president. U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov agreed to meet next week.

Immediate worries focused on eastern Ukraine, where Ukrainian forces have been fighting the pro-Russia rebels since 2014 in a conflict that has killed some 14,000 people.

Ukraine and the separatist leaders traded accusations of escalation. Russia on Saturday said at least two shells fired from a government-held part of eastern Ukraine landed across the border, but Ukraine’s foreign minister dismissed that claim as “a fake statement.”

Top Ukrainian military officials came under a shelling attack during a tour of the front of the nearly eight-year separatist conflict in eastern Ukraine. The officials fled to a bomb shelter before hustling from the area, according to an Associated Press journalist who was on the tour.

The military on Sunday closed a key checkpoint leading to the separatist region after it came under repeated shelling.

Elsewhere on the front lines, Ukrainian soldiers said they were under orders not to return fire. Zahar Leshushun, peering into the distance with a periscope, had followed the news all day from a trench where he is posted near the town of Zolote.

“Right now, we don’t respond to their fire because …” the soldier started to explain before being interrupted by the sound of an incoming shell. “Oh! They are shooting at us now. They are aiming at the command post.”

The Ukrainian military official told Military Times that the only thing stopping an attack from Russia “is they do not have yet casus belli. We are trying to be cool in mind and have warm hearts to understand them what they are looking for.”

Sporadic violence has broken out for years along the line separating Ukrainian forces from the Russia-backed separatists, but the spike seen in recent days is orders of magnitude higher than anything recently recorded by international monitors: nearly 1,500 explosions recorded in 24 hours.

Denis Pushilin, the head of the pro-Russia separatist government in Ukraine’s Donetsk region, cited an “immediate threat of aggression” from Ukrainian forces in his announcement of a call to arms. Ukrainian officials vehemently denied having plans to take rebel-controlled areas by force.

“I appeal to all the men in the republic who can hold weapons to defend their families, their children, wives, mothers,” Pushilin said. “Together we will achieve the coveted victory that we all need.”

A similar statement followed from his counterpart in the Luhansk region. On Friday, the rebels began evacuating civilians to Russia with an announcement that appeared to be part of their and Moscow’s efforts to paint Ukraine as the aggressor.

Metadata from two videos posted by the separatists announcing the evacuation of civilians to Russia show that the files were created two days ago, the AP confirmed. U.S. authorities have alleged that the Kremlin’s effort to come up with an invasion pretext could include staged, prerecorded videos.

Ukraine’s military said two of its soldiers died in firing from the separatist side on Saturday.

Authorities in Russia’s Rostov region, which borders eastern Ukraine, declared a state of emergency because of the influx of evacuees. Media reports on Saturday described chaos at some of the camps assigned to accommodate them.

Putin ordered the Russian government to offer 10,000 rubles (about $130) to each evacuee, an amount equivalent to about half of an average monthly salary in eastern Ukraine.

The separatist regions of Ukraine, like much of the country’s east, are majority Russian speaking. Putin on Tuesday repeated allegations of a “genocide” there in explaining the need to protect them.

One of the evacuees, a Donetsk resident who identified himself only as Vyacheslav, blamed Ukraine’s government for his plight.

“Let them calm down,” he said. “It’s our fault we don’t want to speak Ukrainian, is that it?”

Jim Heintz reported from Moscow. Mstyslav Chernov in Zolote, Ukraine, Geir Moulson in Berlin, Aamer Madhani in Munich, Robert Burns and Darlene Superville in Washington, Liudas Dapkus in Vilnius, Lithuania, Yuras Karmanau in Kyiv and Military Times senior managing editor Howard Altman contributed to this story.

The U.S. Navy says the incident just didn’t happen.

The Russian ministry said it summoned the U.S. embassy’s military attache after its navy detected an American submarine in Russian waters near the Kuril Islands in the Pacific. The submarine declined orders to leave, but departed after the navy used unspecified “appropriate means,” the ministry said.

The U.S. submarine was operating in an area where the Russian navy was conducting military exercises in Russian Federation national waters near the island of Urup in the Kuril archipelago at 10:40 am Moscow time, the MOD claimed.

The ministry claimed that its surface ship communicated with the crew of the submarine via underwater sonar communication systems in Russian and English. It said the U.S. boat was messaged, “You are in the Russian territorial waters right now! Surface immediately!”

The crew of the submarine ignored the communication, the Russians claim.

U.S. Navy officials flatly denied the assertions.

“There is no truth to the Russian claims of our operations in their territorial waters,” said U.S. Navy Capt. Kyle Raines, a spokesman for U.S. Indo-Pacific Command, in a statement. “I will not comment on the precise location of our submarines, but we do fly, sail and operate safely in international waters.”

Asked if there was contact between the two ships in international waters, Raines said there was no encounter at all between the two forces.

The Russians claimed the crew of the frigate Marshal Shaposhnikov used “approved measures in accordance with the documents governing the Russian Federation border protection,” according to the MOD release, which did not specify what those measures were.

The American submarine “used a self-propelled target-splitting imitator on the radio positioning and acoustic control and left the Russian territorial waters at top speed,” according to the release.

The Russian Pacific fleet ships continued the planned military drills, including underwater control to prohibit Russian border violations, the MOD said.

News of the alleged submarine incident came as Russian President Vladimir Putin and U.S. President Joe Biden held a high-stakes telephone call Saturday while a tense world watched and worried that an invasion of Ukraine could begin within days.

Before talking to Biden, Putin had a telephone call with French President Emmanuel Macron, who met with him in Moscow earlier in the week to try to resolve the biggest security crisis between Russia and the West since the Cold War. A Kremlin summary of the call suggested that little progress was made toward cooling tensions.

In a sign that American officials are getting ready for a worst-case scenario, the United States announced plans to evacuate its embassy in the Ukrainian capital, and Britain joined other European nations in urging its citizens to leave Ukraine.

Russia has massed more than 130,000 troops near the Ukraine border and has sent troops to exercises in neighboring Belarus, but denies that it intends to launch an offensive against Ukraine.

The timing of any possible Russian military action remained a key question.

The U.S. picked up intelligence that Russia is looking at Wednesday as a target date, according to a U.S. official familiar with the findings. The official, who was not authorized to speak publicly and did so only on condition of anonymity, would not say how definitive the intelligence was. The White House publicly underscored that the U.S. does not know with certainty whether Putin is committed to invasion.

However, U.S. officials said anew that Russia’s buildup of firepower near Ukraine has reached the point where it could invade on short notice.

Adding to the sense of crisis, the Pentagon ordered an additional 3,000 U.S. troops to Poland to reassure allies. And on Saturday morning, Defense Secretary Lloyd Austin ordered the 160-member Task Force Gator, which was training Ukrainian troops in the western part of the country, to redeploy elsewhere in Europe.

A Kremlin statement about the Putin-Macron call referred to “provocative speculations about an allegedly planned Russian ‘invasion’ of Ukraine.” Russia has consistently denied that it plans military action against its neighbor.

Putin also complained in the call that the United States and NATO have not responded satisfactorily to Russian demands that Ukraine be prohibited from joining the military alliance and that NATO pull back forces from Eastern Europe.

The closely watched call between Biden and Putin began at 11:04 a.m. EST, the White House said. Biden conducted the call from Camp David.

This is a developing story. Stay with Navy Times for updates.