The president said his decision came after an extensive months-long review that included regular discussions with Afghanistan’s leaders, his national security team and U.S. commanders in the field. The move reflected a painful, if predictable, reality on the ground in Afghanistan, where the Taliban has made gains over the last year as Afghan troops have taken over the vast majority of the fighting.

“Afghan forces are still not as strong as they need to be,” Obama said Thursday morning from the White House, explaining his decision. “Meanwhile, the Taliban has made gains particularly in rural areas and can still launch deadly attacks in cities, including Kabul.”

Obama said he will also dramatically slow the pace of the reduction of American forces and plans to maintain the current U.S. force of 9,800 through “most of 2016.” The post-2016 force would still be focused on training and advising the Afghan army, with a special emphasis on its elite counterterror forces. The United States would also maintain a significant counterterrorism capability of drones and Special Operations forces to strike al-Qaeda and other militants who may be plotting attacks against the United States.

The revised troop plans came just weeks after Afghan forces were driven from Kunduz, the first major city to fall to the Taliban since the war began in 2001. Two weeks passed before the Afghans, with some support from U.S. planes and Special Operations advisers, took the city back from the Taliban. Militants are now threatening other cities.

“The bottom line is that in key areas of the country, the security situation is still very fragile, and in some places there’s risk of deterioration,” Obama said.

The president praised the Afghan government, under the leadership of President Ashraf Ghani, as a willing partner, and he lauded the Afghan troops, who have taken significant casualties. Both were critical factors in his decision to keep U.S. troops in the country.

“Every single day, Afghan forces are out there fighting and dying to protect their country,” Obama said. “They are not looking to us do it for them.”

The president acknowledged the strain that the last decade of combat has taken on the U.S. military and America’s broader war weariness. “As you are well aware, I do not support the idea of endless war,” he said.

Obama’s decision follows the collapse of much of the U.S.-trained Iraqi army last summer under pressure from Islamic State militants. White House officials sought to contrast the Obama’s Afghanistan announcement with his 2011 withdrawal of U.S. troops from Iraq, saying the United States had lacked in Baghdad a reliable partner like Ghani.

In Afghanistan, Obama, said, a continued U.S. presence would set the country up for “lasting progress” and help ensure it doesn’t once more become a terrorist haven.

Obama discussed the decision in a call Wednesday with Ghani, who has pressed American officials to commit to staying longer in his country.

Afghan officials welcomed the move. “It’s very positive in light of the continued problems that this region is facing,” said Mohammad Daud Sultanzoy, a presidential candidate in 2014 who is now allied with Ghani.

“Our security have shown the will and capability to fight, but we still need the support of our allies, especially the United States.”

Gen. Sayed Malok, a commander in Ghazni province southwest of Kabul, called it a “good decision at the moment, but a temporary solution.”

“The permanent solution is to train and equip Afghan forces,” said Malok, whose units faced insurgent attacks this week against the provincial capital.

The decision is a significant departure from the exit plan that Obama announced in a White House Rose Garden speech in May 2014. In keeping with his promise to “turn the page” on the costly wars launched by his predecessor, Obama said then that he would reduce the U.S. footprint to around 1,000 troops, all based in Kabul, by the end of 2016.

It is also a stark illustration of how persistent militant threats have stood in the way of Obama’s promises to end the ground wars that have dominated U.S. foreign policy since the Sept. 11, 2001, attacks.

In addition to a resurgent Taliban, al-Qaeda appears to have staked out new ground in Afghanistan, far from the group’s mountain enclaves along the Pakistan border. Last week, U.S. forces launched a major operation against al-Qaeda in Kandahar, launching 63 airstrikes on militant training bases.

Speaking to reporters following Obama’s announcement, aides sought to portray the decision as a natural extension of a strategy that was making progress, rather than an indication that the president’s original plan had failed.

“I don’t think anyone ever intended that the job, so to speak, would be finished” despite Obama’s timetable, said Lisa Monaco, a senior White House official. “We always said that we would continue to have a presence there.”

Under the new plan, the U.S. military will retain bases in Kabul, as planned, but also have forces at Bagram air base and at bases outside Kandahar and Jalalabad, the largest cities in Afghanistan’s southern and eastern regions.

Obama emphasized that Afghans would continue to take the lead role in the fighting, with Americans providing advice and some counterterrorism support from bases outside Kabul. “These bases will give us the presence and the reach our forces require to achieve their mission,” he said.

The change in course acknowledges the struggle that Afghan forces, which are suffering casualties at what military officials have called an “unsustainable” rate, confront as they battle Taliban offensives not just in Kunduz but in Ghazni and other areas. Officials said the announcement was not directly linked to the fall of Kunduz.

“This specific posture has been under consideration for months,” an administration official said.

The larger force of 5,500 troops is projected to cost about $15 billion a year, or about $5 billion more than the smaller, 1,000-person Kabul-based force would have cost.

Although U.S. deaths have fallen off dramatically in recent years, the change may also mean more U.S. casualties. So far this year, 25 American service members and civilians have been killed in the country.

The extended Afghanistan presence will form an imporant part of a global network of counterterrorism facilities that, according to a plan championed by Gen. Martin E. Dempsey, former chairman of the Joint Chiefs of Staff, would allow the United States to better manage acute threats without requiring large conventional forces on the ground.