WASHINGTON (Reuters) – The White House sought to make the case on Monday that President Donald Trump had not changed his position on withdrawing U.S. troops from Syria, a day after his national security adviser outlined conditions for a withdrawal that could take months.

Trump’s abrupt announcement last month that he was bringing home the roughly 2,000 troops in Syria, saying they had succeeded in their mission to defeat Islamic State there, sparked concern among officials in Washington and allies abroad and prompted Defense Secretary Jim Mattis to resign.

In recent days, Trump administration officials have applied the brakes, making clear the withdrawal will not happen quickly. The president himself said last week that the United States would get out of Syria slowly “over a period of time.”

“The president hasn’t changed his position, as he mentioned his primary goal is to ensure the safety of our troops and the safety of our allies as well,” White House spokeswoman Mercedes Schlapp told Fox News on Monday. “And so the Department of Defense will come up with its operational plan to safely withdraw our troops.”

“It takes time to take the troops out because we want to make sure that our troops are safe in this process,” she said.

On Sunday, White House national security adviser John Bolton added a new condition to the U.S. withdrawal from Syria, saying Turkey must agree to protect the United States’ Kurdish allies.

Trump reiterated on Sunday that the United States would pull its troops out of Syria but suggested the move might not happen soon.

Secretary of State Mike Pompeo told CNBC on Monday that the Syria drawdown is a “change of tactics” but reiterated that it does not alter the U.S. commitment to defeat Islamic State and counter Iran’s influence in the region.

Islamic State has been beaten back from large areas of territory it once controlled in Syria. But Trump’s announcement of a U.S. pullout left many questions open, including whether Kurdish fighters who had been operating in northern Syria alongside U.S. forces would be attacked by their long-time enemy, Turkey.

Allies were also concerned that the withdrawal could leave the United States with few options to prevent a resurgence of Islamic State.

As to whether Turkish President Recep Tayyip Erdogan could be trusted not to turn on America’s Kurdish allies in Syria, Pompeo said “Erdogan made a commitment to President Trump” that those who fought with U.S. troops against Islamic State would be protected.

He told CNBC that Bolton was visiting Turkey this week “to have a conversation with the Turks about how they will effectuate that in light of the U.S. withdrawal.”

On Dec. 19, the day he first announced the pullout, Trump said in a video message, referring to the U.S. troops, “They’re all coming back and they’re coming back now. We won.”

At the time, the White House declined to offer a timeline for withdrawal. However, one U.S. official said then that Washington aimed to withdraw troops within 60 to 100 days and a second official said they could leave even sooner.