This story has been updated.

WASHINGTON — President Donald Trump will leave office with 2,500 troops in Afghanistan and 2,500 troops in Iraq after he ordered drawdowns of American forces in both those countries, which were announced Tuesday by his new acting defense secretary.

"By Jan. 15, 2021, our forces, their size in Afghanistan will be 2,500, and our force size in Iraq will also be 2,500 by that same date," acting Defense Secretary Christopher Miller said Tuesday in his first public appearance at the Pentagon since taking the job Nov. 9 after Trump fired former Defense Secretary Mark Esper. “This is consistent with our established plans and strategic objectives supported by the American people and does not equate to a change in U.S. policy or objectives.”

The decision would give military officials about 10 weeks to remove about 2,500 troops from Afghanistan and about 500 from Iraq.

Troops had already been steadily drawing down throughout 2020 from Afghanistan, where the U.S. had 13,000 troops in January. U.S. forces began 2020 with about 5,200 troops in Iraq.

The moves accelerate the rate at which U.S. troops are leaving ahead of the end of Trump’s term on Jan. 20 and against the backdrop of ongoing negotiations for a peace agreement between the U.S.-backed Afghan government and the Taliban. But the hastened drawdowns stop short of achieving Trump’s long-promised end of American involvement in what he has dubbed “forever wars.”

Since Trump was a candidate in 2016, he has championed the full U.S. military exit from places such as Afghanistan, Iraq, Syria and Somalia. He tweeted as recently as October that he wanted all American troops “home by Christmas.”

Defense officials said Tuesday that they had determined the United States could ensure Americans were protected from any threats emanating from Afghanistan or Iraq with the reduced forces. They declined to comment on any planned reductions for the hundreds of troops serving in Somalia and Syria.

Miller is a former Green Beret who was among the first U.S. special operations troops to fight in Afghanistan in late 2001 following al-Qaida’s 9/11 terrorist attacks. He later fought in Iraq, as well. The acting defense secretary said he spent Tuesday morning briefing congressional leaders and allied nations on the U.S. withdrawal. He did not take questions after delivering his statement and did not say what troops would leave Afghanistan or Iraq or precisely what mission the remaining forces have been assigned.

In Afghanistan, for example, U.S. troops in recent years have served two missions — advising Afghan forces and fighting terrorist groups, namely the Islamic State’s affiliate there and remnants of al-Qaida. U.S. troops in Iraq have primarily served in recent years as trainers for Iraqi forces battling the remnants of ISIS.

“The United States Armed Forces remain committed to protecting the safety and security for the American people, and supporting our like-minded allies and partners worldwide,” Miller said. “If the forces of terror, instability, division and hate begin a deliberate campaign to disrupt our efforts, we stand ready to apply the capabilities required to thwart them.”

Despite the drawdowns ordered to be completed just five days before the end of Trump’s administration, senior defense officials, speaking on condition of anonymity, insisted they were recommended by top military officials who they declined to identify. The defense officials said U.S. security officials had also determined they could quickly flow troops back into either country if needed.

It was not immediately clear Tuesday what President-elect Joe Biden’s plans were for either country. He has said he intended to retain a small force in Afghanistan focused on counterterrorism operations.

Some lawmakers on Monday and Tuesday expressed concern about Trump’s ordered cuts, including several Republicans. Senate Majority Leader Mitch McConnell, R-Ky., speaking on the Senate floor Monday, warned a further drawdown of forces Afghanistan could be viewed “as a symbol of U.S. defeat and humiliation and of victory for Islamic extremism.”

“A rapid withdrawal of U.S. forces from Afghanistan now would hurt our allies and delight the people who wish us harm,” he said. "The consequences of a premature American exit would likely be even worse than President [Barack] Obama's withdrawal from Iraq back in 2011, which fueled the rise of ISIS and a new round of global terrorism.”

Rep. Mac Thornberry, R-Texas, warned Tuesday that a further drawdown could harm the ongoing peace negotiations between the Taliban and the Afghan government, which began in September.

In its Feb. 29 agreement with the Taliban, the United States agreed to a full withdrawal of its forces by May 2021 contingent on a number of conditions the Taliban must meet, including cutting ties to terrorist groups and refraining from attacks on U.S. and NATO troops.

“I don't know of any condition which justifies reducing further the troops that we have in Afghanistan,” Thornberry, the retiring top Republican on the House Armed Service Committee, said Tuesday before the Pentagon’s official announcement. “As a matter of fact, I think it undercuts the negotiations to say [to the Taliban], ’Well, whatever you do or don't do, we're going to reduce our troops even further.’ And, so I am concerned.”

But Rep. Adam Smith, D-Wash., chairman of the House Armed Service Committee, said he agreed with the reduction to 2,500 troops in Afghanistan.

“At the same time, this reduction must be responsibly and carefully executed to ensure stability in the region,” he said in a statement. “While the history of conflict in the region is complex and predates our direct involvement, after nearly 20 years of armed conflict, Americans and Afghans alike are ready for the violence to end. It is clear that groups like ISIS-K and the Taliban will continue to fight and sow chaos, but ultimately it is up to the Afghans to find a sustainable path to peace.

The chairman of Senate Armed Services Committee, Sen. Jim Inhofe, R-Okla., also expressed support for the plan Tuesday.

Rep. Jason Crow, D-Colo., a former Army Ranger who fought in Iraq and Afghanistan, said he wants to see the war in Afghanistan end, but it must be done correctly.

“We must do so in a deliberate way that both protects our troops and keeps faith with the allies who came to our aid after 9/11 and still serve with us to this day,” Crow said in a statement issued Tuesday. “There is a right way to do this, but President Trump has instead chosen to play politics. Our troops, the American people, and our allies deserve better.”

The U.N. in June reported the Taliban had not cut ties with al-Qaida since forging the agreement with the United States and had begun working more closely with the 400-600 al-Qaida fighters remaining in Afghanistan.

Marine Gen. Kenneth F. McKenzie, the commander of U.S. Central Command, warned after that report that he had not seen indications the Taliban were serious about meeting some of the conditions in the agreement.

McKenzie has publicly pushed back against a full withdrawal of U.S. forces from either Afghanistan or Iraq. But senior defense officials said Tuesday that McKenzie and Army Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, were involved in the planning before Trump's order.

Miller said Tuesday in his brief remarks that he celebrated Trump’s decision, calling it a step toward the end of generational wars.

“Today is another critical step in that direction, and a result of President Trump's bold leadership with the blessings of Providence in the coming year, we will finish this generational war, and bring our men and women home,” he said. “We will protect our children from the heavy burden and toll of perpetual war, and we will honor the sacrifices made in service to peace and stability in Afghanistan, Iraq, and around the world.”

dickstein.corey@stripes.com Twitter: @CDicksteinDC