On Thursday, two South Korean KF-16 fighter jets mistakenly released four MK-82 bombs each on a civilian area in Pocheon, a city near the tense border with North Korea. The bombing, which injured nearly 30 people, two of them seriously, occurred when South Korean and U.S. forces were engaging in a live-fire drill in connection with their broader Freedom Shield command post exercise set to begin Monday.

This year’s Freedom Shield exercise is the allies’ first major joint training since President Donald Trump returned to office in January and comes amid concerns about North Korea’s booming military cooperation with Russia.

South Korea and the U.S. announced details of the exercises Thursday, but it was overshadowed by the news of the bombing, which drew intense public criticism in South Korea.

Both the South Korean and U.S. militaries halted all live-fire exercises across South Korea. Military officials said that South Korea’s air force also stopped the flights of its entire aircrafts except surveillance planes and others needed for emergency situations.

Military officials said the Freedom Shield training will proceed as scheduled and they plan to restart live-fire and flight training after they find the exact cause of the bombing and formulate preventative steps.

But if they fail to resume the paused training by Monday when they kick off the Freedom Shield exercise with the U.S. military, that will hurt the workings of the early parts of the exercise, observers say.

Lee Illwoo, an expert with the Korea Defense Network in South Korea, said the suspension of flight training would particularly cause “really a big problem in examining the two countries’ operational plans.” He said flying warplanes would be essential to determining their actual capabilities, discussing the size of reinforcements of U.S. aircraft from abroad and modifying the allies’ operational plans.

Initial investigations found the pilot of one of the KF-16s entered the wrong coordinates for a bombing site. Officials said the pilots of two KF-16s had more than 200-400 hours of flying time. Lee said they likely piloted KF-16s only two to three years.

The South Korean and U.S. militaries have already begun field exercises in connection with the Freedom Shield, and Thursday’s live-fire drill was one of them. Col. Ryan Donald, spokesperson for the U.S. military in South Korea, confirmed that American servicemembers were participating in Thursday’s live-fire training but no U.S. air force aircraft was still involved.

“We take this incident very seriously. We are coordinating closely with the ROK Ministry of Defense and are committed to a thorough and transparent investigation,” Donald said in a statement, using the acronym of South Korea’s official name, the Republic of Korea.

The incident happened as North Korea was ramping up its fiery rhetoric against the U.S. and South Korea, as it views their joint drills as invasion rehearsals. North Korea’s state news agency warned Friday that the U.S. and South Korea “will have to pay dearly for their stupid and reckless war drills.”

Trump has said he would reach out to North Korean leader Kim Jong Un again to revive diplomacy, but North Korea hasn’t responded to his overture.

In South Korea, there were concerns that Trump might scale back U.S.-South Korean military drills because, during his first term, he complained about the cost of bilateral exercises and once unilaterally announced the cancellation of one drill after his first summit with Kim.

But Lee said Trump now knows the importance of South Korea in America’s Indo-Pacific and China policies and won’t downsize drills with South Korea.

This year’s field training being held alongside the Freedom Shield involves 16 brigade-level field trainings, up from 10 such drills last year, according to South Korea’s military.

The arrival of the carrier Carl Vinson and its strike group at the South Korean port of Busan was meant to display a solid U.S-South Korean military alliance in the face of persistent North Korean threats, and boost interoperability of the allies’ combined assets, the South Korean navy said in a statement.

It said it was the first U.S. aircraft carrier to travel to South Korea since June.

The deployment of the carrier is expected to infuriate North Korea, which views temporary deployments of such powerful U.S. military assets as major security threats. North Korea has responded to some of the past deployments of U.S. aircraft carriers, long-range bombers and nuclear-powered submarines with missile tests.

Since his Jan. 20 inauguration, U.S. President Donald Trump has said he will reach out to North Korean leader Kim Jong Un again to revive diplomacy. North Korea hasn’t directly responded to Trump’s overture but alleged U.S.-led hostilities against North Korea have intensified since Trump’s inauguration.

North Korea said Friday it test-fired strategic cruise missiles earlier last week to inform its adversaries of its military’s counterattack capability and the readiness of its nuclear operations. After watching the launches, the North’s fourth missile testing event this year, Kim said the military must be fully ready to use its nuclear weapons

Experts say Kim won’t likely accept Trump’s overture anytime soon as he is now focusing on his support of Russia’s war against Ukraine with the provision of weapons and troops. They say Kim could consider resuming diplomacy with Trump when he thinks he cannot maintain his country’s current booming cooperation with Russia

Kim and Trump met three times from 2018-19 during Trump’s first term to discuss the future of North Korea’s nuclear program. Their high-stakes diplomacy eventually collapsed due to wrangling over U.S.-led economic sanctions on North Korea.

The National Intelligence Service said in a brief statement it was trying to determine exactly how many more troops North Korea has deployed to Russia.

The NIS also assessed that North Korean troops were redeployed at fronts in Russia’s Kursk region in the first week of February, following a reported temporary withdrawal from the area. Ukrainian President Volodymyr Zelenskyy, in an address on Feb. 7, confirmed a new Ukrainian offensive in Kursk and said North Korean troops were fighting alongside Russian forces there.

North Korea has been supplying a vast amount of conventional weapons to Russia, and last fall it sent about 10,000-12,000 troops to Russia as well, according to U.S., South Korean and Ukraine intelligence officials. North Korean soldiers are highly disciplined and well trained, but observers say they’ve become easy targets for drone and artillery attacks on Russian-Ukraine battlefields due to their lack of combat experience and unfamiliarity with the terrain.

In January, the NIS said about 300 North Korean soldiers had died and another 2,700 had been injured. Zelenskyy earlier put the number of killed or wounded North Koreans at 4,000, though U.S. estimates were lower at around 1,200.

Earlier Thursday, South Korea’s JoongAng Ilbo newspaper, citing unidentified sources, reported that an additional 1,000-3,000 North Korean soldiers were deployed to Kursk between January and February.

South Korea, the U.S. and their partners worry that Russia could reward North Korea by transferring high-tech weapons technologies that can sharply enhance its nuclear weapons program. North Korea is expected to receive economic and other assistance from Russia as well.

During talks in Saudi Arabia last week, Russia and the U.S. agreed to start working toward ending the war and improving their diplomatic and economic ties. Ukrainian officials weren’t present at the talks. That marked an extraordinary shift in U.S. foreign policy under President Donald Trump and a clear departure from U.S.-led efforts to isolate Russia over its war in Ukraine.

Observers say North Korean leader Kim Jong Un could send more troops to Russia to win further Russian assistance before the war ends.

Austin told reporters Wednesday “What exactly they are doing? Left to be seen. These are things that we need to sort out,” according to a video posted by the Washington Post.

If the troops join the war in Ukraine on Russia’s side, it will be “a very, very serious issue,” Austin said, adding it would have an impact in Europe and in the Indo-Pacific region.

South Korean intelligence first publicized reports that the Russian navy had taken 1,500 North Korean special warfare troops to Russia last week, while Ukrainian President Volodymyr Zelenskyy had earlier said his government had intelligence that 10,000 North Korea soldiers were being prepared to join the invading Russian forces.

The U.S. and NATO had not previously formally confirmed North Korea’s reported troop dispatch, but have warned of the danger of such a development if true. Russia and North Korea have so far denied the troop movements.

South Korean National Intelligence Service Director Cho Tae-yong told lawmakers that said another 1,500 North Korean troops have entered Russia in a closed-door meeting, according to lawmaker Park Sunwon, who attended the briefing.

Cho told lawmakers that his agency assessed that North Korea aims to deploy a total of 10,000 troops to Russia by December, Park told reporters.

Park cited Cho as saying the 3,000 North Korean soldiers sent to Russia have been split among multiple military bases and are in training. Cho told lawmakers that NIS believes they have yet to be deployed in battle, according to Park.

Speaking jointly with Park about the NIS briefing, lawmaker Lee Seong Kweun said that the NIS found that the Russian military is now teaching those North Korean soldiers how to use military equipment such as drones.

Lee cited the NIS chief as saying Russian instructors have high opinions of the morale and physical strength of the North Korean soldiers but think they will eventually suffer a heavy causalities because they lack an understanding of modern warfare. Lee, citing Cho, said Russia is recruiting a large number of interpreters.

Lee said NIS has detected signs that North Korea is relocating family members of soldiers chosen to be sent to Russia to special sites to isolate them.

The NIS chief told lawmakers that North Korea hasn’t disclosed its troop dispatch to its own people. But there are rumors that the news is spreading to local residents, including those whose loved ones have been assigned Russian tours, Lee said, citing the NIS.

Ukraine’s Military Intelligence Directorate head, Kyrylo Budanov, told the online military news outlet The War Zone that North Korean troops will arrive to Russia’s Kursk region today to help Russian troops fighting off a Ukrainian incursion.

North Korea and Russia, embroiled in separate confrontations with the West, have been sharply boosting their cooperation in the past two years. In June, they signed a major defense deal requiring both countries to use all available means to provide immediate military assistance if either is attacked.

The NIS said last week that North Korea had sent more than 13,000 containers of artillery, missiles and other conventional arms to Russia since August 2023 to replenish its dwindling weapons stockpiles.

Reports that the North is sending troops to Russia stoked security jitters in South Korea. South Korean officials worry that Russia may reward North Korea by giving it sophisticated weapons technologies that could boost the North’s nuclear and missile programs that target South Korea.

South Korea said Tuesday it would consider supplying weapons to Ukraine in response to the North’s reported troop dispatch. South Korea has shipped humanitarian and financial support to Ukraine, but it has so far avoided directly supplying arms to Ukraine in line with its policy of not supplying weapons to countries actively engaged in conflicts.

North Korea has 1.2 million troops, one of the largest standing armies in the world, but it hasn’t fought in large-scale conflicts since the 1950-53 Korean War. Many experts question how much North Korean troops would help Russia, citing a shortage of battle experience. They say North Korea wants to get Russian economic support and its help to modernize the North’s outdated conventional weapons systems as well as its high-tech weapons technology transfers.

North Korea has repeatedly vowed to expand its nuclear arsenal, but the latest threat by Kim Yo Jong came after North Korea dialed up regional tensions by unveiling a uranium-enrichment facility and testing a new ballistic missile earlier this month.

In a statement carried by state media, Kim Yo Jong said that the submarine’s visit “clearly reveals the frantic military and strategic attempt of the U.S.” She said North Korea’s nuclear war deterrent must be bolstered “both in quality and quantity continuously and limitlessly” in response.

“The U.S. strategic assets will never find their resting place in the region of the Korean Peninsula,” she said. “We will continue to inform that all the ports and military bases of the ROK are not safe places.” ROK stands for the Republic of Korea, South Korea’s formal name.

Her comments suggested North Korea may test-fire a missile whose range covers a South Korean site where the U.S. submarine is docked, some observers say.

South Korea’s military said the Vermont, a nuclear-powered and fast-attack submarine, arrived at the southeastern South Korean port city of Busan on Monday to take on supplies and allow its crew to rest.

Temporary deployments of powerful U.S. military assets like aircraft carriers, nuclear-powered submarines and bombers to South Korea are not unusual, but Washington has boosted them over the last year in a show of force against North Korea’s evolving nuclear threats.

Pyongyang often responds furiously to such visits, calling them proof of hostile intentions, and reacts with missile tests.

On Sept. 13, North Korea’s state media published photos of a secretive facility to enrich uranium for nuclear weapons. It was North Korea’s first unveiling of a uranium-enrichment facility since it showed one at the country’s main Yongbyon nuclear complex to visiting American scholars in 2010. Last week, North Korea tested a newly built ballistic missile designed to carry what it calls “a 4.5-ton super-large conventional warhead” and a modified cruise missile.

Since late May, North Korea has also floated thousands of trash-carrying balloons toward South Korea in a Cold War-style psychological campaign, prompting South Korea to restart anti-Pyongyang propaganda loudspeaker broadcasts at border areas.

South Korea’s military warned Tuesday of unspecified military action if the North pushes its balloon campaign to a point that seriously threatens the safety of South Korean civilians.

Military spokesperson Lee Sung Joon didn’t say what action South Korea could take, but he reiterated that the military isn’t considering shooting down the balloons midair because they could be carrying hazardous substances.

So far, North Korea’s balloon activities haven’t caused serious damage.

Associated Press writer Kim Tong-hyung contributed to this report.

The drill — seen as a show of force against North Korea — comes as tensions are rising over the North’s recent launches of rubbish-carrying balloons toward South Korea and other provocations.

Wednesday’s training involved other advanced U.S. and South Korean fighter jets as well as the B-1B aircraft, the second U.S. bomber temporarily deployed over the Korean Peninsula this year. The exercise was meant to demonstrate the U.S. security commitment to South Korea and strengthen the allies’ joint defense posture, according to the South Korean Defense Ministry.

During the training, the B-1B dropped Joint Direct Attack Munitions while being escorted by South Korean jets, the first such bombing drill for a U.S. bomber since 2017, a ministry statement said.

It said South Korean fighter jets also conducted live-firing exercises to demonstrate the country’s readiness to punish North Korea if provoked, it said.

JDAM bombs can include “bunker-buster” explosives. JDAM is a guidance system that converts unguided, conventional bombs into more precise, GPS-guided weapons. All U.S. fighter jets, bombers and drones can use JDAMs, and the munitions are among the weapons systems the United States has been providing to Ukraine to help it fight Russia’s invasion.

North Korea is extremely sensitive to drills using bunker-buster bombs, which could threaten its leadership and complex web of underground military tunnels and structures.

A B-1B is capable of carrying a large conventional weapons payload. North Korean has previously called the bomber’s deployment proof of U.S. hostility. North Korea has responded to past flights of B-1Bs and other powerful U.S. aircraft in South Korea with its own missile tests.

In the past week, North Korea floated hundreds of huge balloons to drop manure, cigarette butts, scraps of cloth and waste batteries across South Korea, in anger over previous campaigns by South Korean civilians to send balloons with leaflets and other items into North Korea. South Korea responded with a promise to take “unbearable” retaliatory steps and suspended a fragile military deal with North Korea calling on both sides to reduce tensions along their border.

The suspension of the 2018 inter-Korean deal allows South Korea to resume military activities like live-fire drills or anti-North Korean propaganda broadcasts via loudspeakers in border areas. Such steps will likely prompt North Korea to take provocative steps in response.

Recently, North Korea launched a rocket in an attempt to place a second spy satellite into orbit in violation of U.N. resolutions, but it blew up shortly after liftoff. It also test-fired nuclear-capable weapons for a drill simulating a preemptive strike on South Korea, and allegedly jammed GPS navigation signals in South Korea.

Since 2022, North Korea has sharply accelerated the pace of missile tests in what foreign experts call an attempt to build a bigger nuclear arsenal and increase its leverage in future diplomacy with the U.S. Nuclear disarmament negotiations between Pyongyang and Washington remain dormant since 2019.

North Korea has conducted six rounds of missile tests so far this year, most of them reportedly involving cruise missiles that typically fly at a low altitude to overcome opponents’ missile defenses. Analysts say that in the event of a conflict, North Korea aims to use cruise missiles to strike U.S. aircraft carriers as well as U.S. military bases in Japan.

South Korea’s air force said in a statement the drill on Friday involved fifth-generation stealth F-35A fighter jets from both countries and other fighter jets from South Korea. It said the U.S. F-35As were deployed in South Korea on Wednesday from Kadena Air Base in Okinawa, Japan.

North Korea has ramped up its weapons tests since 2022 in what experts call an attempt to increase its leverage in future diplomacy. South Korea and the U.S. have responded by expanding their military exercises and trilateral training with Japan.

On the sidelines of a G20 meeting in Rio De Janeiro on Thursday, the top diplomats from South Korea, the U.S. and Japan agreed to strengthen their joint response capability against North Korea’s evolving nuclear threats and coordinate to block the North’s financing of its nuclear program, according to South Korea’s Foreign Ministry.

This year, North Korea is expected to step up its testing activities and belligerent rhetoric as both the U.S and South Korea head into elections. North Korea is likely seeking international recognition as a nuclear state, a status that experts say the North thinks would help it receive relief from U.S.-led economic sanctions.

North Korea’s advancing nuclear arsenal has likely emboldened its stance, and there are concerns that the North may launch a limited military provocation against the South. Observers say a full-scale attack is unlikely as the North is outgunned by more superior U.S. and South Korean forces.

U.S. and South Korean officials have repeatedly warned that any nuclear attack by North Korea against them would spell the end of the North’s government, led by Kim Jong Un.

SEOUL, South Korea — North Korea fired a suspected intermediate-range ballistic missile into the sea on Sunday, South Korea’s military said, two months after the North claimed to have tested engines for a new harder-to-detect missile capable of striking distant U.S. targets in the region.

The launch was the North’s first this year. Experts say North Korea could ramp up its provocative missile tests as a way to influence the results of South Korea’s parliamentary elections in April and the U.S. presidential election in November.

South Korea’s Joint Chiefs of Staff said in a statement that it detected the launch of a ballistic missile of an intermediate-range class from the North’s capital region on Sunday afternoon. It said the missile flew about 1,000 kilometers (620 miles) before landing in the waters between the Korean Peninsula and Japan.

The Joint Chiefs of Staff called the launch a provocation that poses a serious threat to peace on the Korean Peninsula. It said South Korea’s military will maintain its readiness to overwhelmingly respond to any provocations by North Korea.

The South Korean assessment suggests North Korea could have launched a new intermediate-range ballistic missile, whose solid-fuel engine it said it had tested in mid-November.

The missile is mainly designed to hit U.S. military bases in the U.S. Pacific territory of Guam, which is about 3,400 kilometers (2,110 miles) from Pyongyang, the North’s capital. With a range adjustment, the missile can also be used to attack closer targets — the U.S. military installations in Japan’s Okinawa island, according to Chang Young-keun, a missile expert at the Korea Research Institute for National Strategy in Seoul.

Built-in solid propellants make missile launches harder to detect than liquid-fueled missiles, which must be fueled before launch and cannot last long. North Korea has a growing arsenal of solid-fuel short-range missiles targeting South Korea, but its existing Hwasong-12 intermediate-range missile is powered by liquid-fuel engines.

Japan’s Defense Ministry said its analysis showed the missile traveled at least 500 kilometers (300 miles) at the maximum altitude of 50 kilometers (30 miles), data that suggest North Korea may have fired a short-range and not an intermediate-range missile.

Japan and South Korea said they closely exchanged information about the launch with the United States, but they didn’t immediately explain the discrepancy in data.

In a trilateral call later Sunday, senior diplomats from South Korea, the U.S. and Japan condemned the North Korean launch and stressed that a North Korean provocation would lead to the three countries strengthening their security cooperation, according to South Korea’s Foreign Ministry.

The last time North Korea performed a missile launch that was publicly announced was Dec. 18, when it test-fired its Hwasong-18 solid-fueled intercontinental ballistic missile, the North’s most advanced weapon. The Hwasong-18 is the country’s only known solid-fuel ICBM and it’s designed to strike the mainland U.S.

On Jan. 5, North Korea fired a barrage of artillery shells near the disputed western sea boundary with South Korea, prompting South Korea to conduct similar firing exercises in the same area. South Korea accused North Korea of continuing similar artillery barrage in the area for the next two days. The site is where the navies of the two Koreas have fought three bloody sea battles since 1999, and attacks blamed on North Korea killed 50 South Koreans in 2010.

In recent days, North Korea has also been escalating its warlike, inflammatory rhetoric against its foes ahead of an election year in South Korea and the U.S. Leader Kim Jong Un, during visits last week to munitions factories, called South Korea “our principal enemy” and threatened to annihilate it if provoked.

Experts say Kim likely wants to see South Korean liberals win the election in a blow to conservative President Yoon Suk Yeol, who has taken a hard line on the North. They say Kim also wants former U.S. President Donald Trump to be elected again because he may believe he could win U.S. concessions if Trump returns to the White House.

Kim has been pushing hard to enlarge his nuclear and missile arsenals since his high-stakes diplomacy with Trump broke down in 2019. In recent months, North Korea has also been expanding its military and other cooperation with Russia.

The U.S. government said it has evidence that missiles provided by North Korea to Russia had been used in the war in Ukraine. In a joint statement last week, the U.S., South Korea and their partners said the missile transfer supports Russia’s war of aggression and provides North Korea with valuable technical and military insights.

North Korea and Russia announced Sunday that North Korean Foreign Minister Choe Son Hui will visit Russia from Monday to Wednesday at the invitation of her Russian counterpart Sergey Lavrov.

“Pyongyang’s show of force should be of concern beyond Seoul, as its military cooperation with Moscow adds to the violence in Ukraine, and because it may be more willing to challenge the U.S. and its allies while global attention is fixed on the Middle East,” said Leif-Eric Easley, a professor at Ewha University in Seoul.

Associated Press writer Mari Yamaguchi in Tokyo contributed to this report.

North Korea has increased its warlike rhetoric in recent months in response to an expansion of U.S.-South Korean military drills. Experts expect Kim will continue to escalate his rhetoric and weapons tests because he likely believes he can use heightened tensions to wrest U.S. concessions if former President Donald Trump wins the U.S. presidential election in November.

In a five-day major ruling party meeting last week, Kim said he will launch three more military spy satellites, produce more nuclear materials and develop attack drones this year in what observers say is an attempt to increase his leverage in future diplomacy with the U.S.

In a meeting Sunday with commanding army officers, Kim said it is urgent to sharpen “the treasured sword” to safeguard national security, an apparent reference to his country’s nuclear weapons program. He cited “the U.S. and other hostile forces’ military confrontation moves,” according to the official Korean Central News Agency.

Kim stressed that “our army should deal a deadly blow to thoroughly annihilate them by mobilizing all the toughest means and potentialities without moment’s hesitation” if they opt for military confrontation and provocations against North Korea, KCNA said.

In his New Year’s Day address Monday, South Korean President Yoon Suk Yeol said he will strengthen his military’s preemptive strike, missile defense and retaliatory capabilities in response to the North Korean nuclear threat.

“The Republic of Korea is building genuine, lasting peace through strength, not a submissive peace that is dependent on the goodwill of the adversary,” Yoon said, using South Korea’s official name.

At the party meeting, Kim called South Korea “a hemiplegic malformation and colonial subordinate state” whose society is “tainted by Yankee culture.” He said his military must use all available means including nuclear weapons to “suppress the whole territory of South Korea” in the event of a conflict.

South Korea’s Defense Ministry warned in response Sunday that if North Korea attempts to use nuclear weapons, South Korean and U.S. forces will punish it overwhelmingly, resulting in the end of the Kim government.

KCNA said North Korean officials held talks on Monday to implement an order by Kim to disband or reform organizations handling relations with South Korea to fundamentally change the principle and direction of the North’s struggle against the South. There was no immediate explanation of how that might alter inter-Korean relations, which have been stalled for an extended period.

Experts say small-scale military clashes between North and South Korea could happen this year along their heavily armed border. They say North Korea is also expected to test-launch intercontinental ballistic missiles capable of reaching the mainland U.S. and other major new weapons.

In 2018-19, Kim met Trump in three rounds of talks on North Korea’s expanding nuclear arsenal. The diplomacy fell apart after the U.S. rejected Kim’s offer to dismantle his main nuclear complex, a limited step, in exchange for extensive reductions in U.S.-led sanctions.

Since 2022, North Korea has conducted more than 100 missile tests, prompting the U.S. and South Korea to expand their joint military exercises. North Korea has also tried to strengthen its relationships with China and Russia, which blocked efforts by the U.S. and its partners in the U.N. Security Council to toughen U.N. sanctions on North Korea over its weapons tests.

KCNA said Kim and Chinese President Xi Jinping exchanged New Year’s Day messages on Monday on bolstering bilateral ties. North Korea faces suspicions that it has supplied conventional arms for Russia’s war in Ukraine in return for sophisticated Russian technologies to enhance the North’s military programs.

Estimates of the size of North Korea’s nuclear arsenal vary, ranging from about 20-30 bombs to more than 100. Many foreign experts say North Korea still has some technological hurdles to overcome to produce functioning nuclear-armed ICBMs, though its shorter-range nuclear-capable missiles can reach South Korea and Japan.

The trilateral training off South Korea’s southern island of Jeju was meant to strengthen the countries’ joint response against North Korean nuclear threats, South Korea’s Joint Chiefs of Staff said in a statement.

The exercise involved B-1B bombers and South Korean and Japanese fighter jets, the statement said. It said the B-1Bs’ flyover is the 13th time that a U.S. bomber has been temporarily deployed near and over the Korean Peninsula this year.

The B-1B is capable of carrying a large conventional weapons payload. North Korean has previously called the bomber’s deployment a proof of U.S. hostility and had reacted with missile tests.

North Korea on Monday launched a Hwasong-18 ICBM into the sea in a drill it said was meant as a warning over the U.S. and South Korea’s confrontational steps. North Korea cited a recent U.S.-South Korean meeting to discuss their nuclear deterrence plans.

The U.S., South Korea and Japan slammed the launch as a provocation, noting it violated multiple U.N. Security Council resolutions that ban any ballistic activities by the North.

The Hwasong-18, a solid-fueled missile, is the North’s newest and most advanced ICBM. Its built-in solid propellant makes launches harder to detect than liquid-fueled missiles, which must be fueled for liftoffs. Monday’s launch is the Hwasong-18′s third firing this year.

North Korean leader Kim Jong Un said the launch showed how North Korea could respond if the United States were to make “a wrong decision against it.” But many foreign experts say the North still has technological obstacles to overcome to possess functioning nuclear-armed ICBM that can hit the continental U.S.

Since last year, North Korea has conducted about 100 ballistic missile tests in what outside experts call a bid to modernize its nuclear arsenal and win greater U.S. concessions. In response, the U.S. and South Korea expanded their military drills, strengthened security cooperation with Japan and increased the temporary deployment of powerful U.S. military assets such as bombers and nuclear-powered submarines in South Korea.

Despite its torrid run of ballistic missile tests, North Korea has avoided new international sanctions as China and Russia, both permanent members of the U.N. Security Council, stymied any council responses to the North’s testing activities. In an emergency U.N. Security Council meeting Tuesday over the North’s ICBM launch, North Korean and Russian diplomats clashed with U.S., South Korean and other diplomats.