WASHINGTON — The US administration is struggling to get European allies to commit troops for Syria, even as some administration officials have tried to walk back President Donald Trump’s surprise announcement in December that he was ordering US forces to leave Syria over the coming months.

The State Department on Tuesday declined to confirm an estimate of 400 US forces remaining in Syria for some indeterminate amount of time previously offered by the White House, but said talks continue with partner nations about the composition of what it called a multinational force to prevent the re-emergence of the so-called Islamic State (IS or ISIS) in northeast Syria.

“A residual force of the United States military is going to remain in northeast Syria as part of a multinational force in order to prevent ISIS resurgence and to support stability and security in northeast Syria,” State Department deputy spokesman Robert Palladino told journalists at the State Department press briefing Tuesday.

“The drawdown is going to continue,” Palladino said. “And as we … transition, we’re going to continue to be working with our allies and partners to clear liberated areas, conduct targeted counterterrorism operations and support stabilization efforts.”