President Barack Obama on Wednesday announced a draw down of about 1,400 U.S. troops from Afghanistan by the end of this year, leaving more than 8,4000 service members deployed to the war-torn country through the end of his presidency.

"I strongly believe that it is in our national security interest, especially after all the blood and treasure we've invested in Afghanistan over the years, that we give our Afghan partners the very best opportunity to succeed," he said.

"The decision I'm making today ensures that my successor has a solid foundation for continued progress in Afghanistan as well as the flexibility to address the threat of terrorism as it evolves."

Flanked by Defense Secretary Ash Carter and Joint Chiefs Chairman Gen. Joseph Dunford, Obama said his national security advisers recommended moving away from previous pledges to reduce the U.S. military presence in Afghanistan draw down to 5,500 troops. 

Senior administration officials said the decision was based largely on military assessments made in recent weeks by Army Gen. John Nicholson Jr., who commands all NATO forces there. 

The president said the current mission of advising and assisting local Afghan security forces will not change, noting that the military's combat mission in country ended two years ago. American special operations forces also conduct targeted counter-terror missions there. Faced with a resurgent Taliban, the White House last month approved plans to give American commanders greater liberty to use airstrikes whenever U.S. or Afghan troops are in danger.

"As president and commander and chief, I've made it clear that I will not allow Afghanistan to be used as safe haven for terrorists to attack our nation again," Obama vowed.

Nicholson assumed command of the Afghanistan mission in March. As part of his review, he considered the Afghan security forces' viability and the fragile political dynamics that could bring about peace talks with the Taliban, officials said. Nicholson submitted his recommendations in June. Around the same time, the president agreed to loosen restrictions on the use of airstrikes.

U.S. taxpayers are spending more than $4 billion annually to support the Afghan military, whose many challenges have been detailed and documented by the special inspector general for Afghanistan reconstruction, John Spoko. His most recent report to Congress indicates "neither the United States nor its Afghan allies know how many Afghan soldiers and police actually exist, how many are in fact available for duty, or, by extension, the true nature of their operational capabilities."

However, Obama framed his decision not as a failure of the Afghan forces to step up to the task of defending their own country. Instead, he cited the difficulty of standing up a wholly new military in just a few years.

"It has been continually my belief that it is up to Afghans to defend their country," the president said. "Because we have emphasized training their capabilities, we've been able to end our major ground war there and bring 90 percent of our troops back home. But even as we work for peace, we have to deal with the realities of the world as it is."

"We can't forget what's at stake in Afghanistan. This is where al Qaida is trying to regroup, this is where ISIL continues to try to expand its presence," he added, using an acronym for the Islamic State terror group.

Two years ago, in a similar White House speech, Obama promised to reduce the U.S. troop presence in Afghanistan to 9,800 by the start of 2015, then to around 5,000 by the start of 2016, and finally to a "normal embassy presence in Kabul, with a security assistance component" by the start of 2017.

But the president has maintained the American military presence at just under 10,000 troops since early 2015 at the advice of Defense Department advisers, who have admitted that training local security forces to independently battle insurgents has taken longer than anticipated.

Leading congressional Republicans and some Democrats have pushed in recent months for the president to maintain U.S. troop levels in the region, citing continued attacks by Taliban fighters and the growing threat posed by Islamic State advances in the country.

Republicans on Capitol Hill quickly blasted the president's troops cuts as more politics than sound strategy.

"The precision of the president's new Afghanistan troop cap would be comical were its consequences not so tragic for our mission and military readiness," said Rep. Mac Thornberry, R-Texas, chairman of the House Armed Services Committee.

"It is time that the president level with the American people about what it will really take to achieve our goals in Afghanistan, and how much it will cost. The truth is that many thousands more Americans are performing military functions in Afghanistan than even the current troop cap authorizes."

Thornberry said Obama needs to request a new war supplemental to pay for the ongoing operations in Afghanistan for the rest of 2016 and coming years, a point of contention among Congress and the White House.

Administration officials said they will work with lawmakers in coming months to ensure that the continued mission in Afghanistan is adequately funded.

Senate Armed Services Committee Chairman Sen. John McCain, R-Ariz., praised Obama's decision not to drop force levels down to 5,500 but added "when the president himself describes the security situation in Afghanistan as 'precarious,' it is difficult to discern any strategic rationale for withdrawing 1,400 U.S. troops by the end of the year."

Wednesday's announcement leaves ending the fight in Afghanistan — a key campaign promise made by Obama ahead of his 2008 election — to the next commander in chief, the third to oversee the war there. October will mark 15 consecutive years of U.S. military presence in the war-torn country.

Obama noted on Wednesday that 38 Americans have died in insurgent attacks in Afghanistan in the last year, including U.S. troops, contractors and aid workers.

Leo Shane III covers Congress, Veterans Affairs and the White House for Military Times. He can be reached at