The United States urged other countries Monday to bring home hundreds of Islamic State sympathizers captured in Syria, a delicate issue for allies such as France as Washington withdraws troops.

After allies grappled for weeks on what to do with the extremists left in Syria, the United States came down clearly on the side of repatriation.

The United States said that the Kurdish-led Syrian Democratic Forces (SDF) -- which played a major role in crushing the Islamic State group and has warned that it may not be able to guard its jails once US troops leave   had been holding the jihadists “securely and humanely.”

“The United States calls upon other nations to repatriate and prosecute their citizens detained by the SDF and commends the continued efforts of the SDF to return these foreign terrorist fighters to their countries of origin,” State Department spokesman Robert Palladino said in a statement.

The announcement comes two days before foreign ministers of US allies are set to meet in Washington for talks on the anti-IS coalition, with question marks on how to move forward without the military backing of the United States.

President Donald Trump on December 19 stunned Western allies by announcing that the United States will pull its 2,000 troops out of Syria, declaring that the Islamic State movement, also known as ISIS, had been defeated.

In a carefully worded statement, the State Department conceded that the group still had fighters who pose concerns.

“Despite the liberation of ISIS-held territory in Iraq and Syria, ISIS remains a significant terrorist threat and collective action is imperative to address this shared international security challenge,” Palladino said.

Fears in France

One of the countries most concerned is France, which has been hit by a series of attacks inspired by the Islamic State group including the grisly November 2015 siege of the Bataclan nightclub.

Paris last week opened the door to bringing back its citizens, after earlier insisting that the jihadists should be prosecuted locally and not step foot back in France.

The French foreign ministry said its goal was to “avoid the escape and scattering of these potentially dangerous individuals” and acknowledged that the situation on the ground was changing with the US withdrawal.

A French security source, speaking on condition of anonymity, earlier told AFP that 130 people could be repatriated. A second French official said the group included 70 to 80 children held with their mothers.

The Syrian Democratic Forces are worried that, without US troops as a buffer, they will be crushed by neighboring Turkey   which equates them with Kurdish separatists at home and had encouraged Trump to withdraw US forces.

Shortly after Trump’s announcement, the SDF warned that it would pull back from the battle against the Islamic State movement if Turkey attacked.

SDF leaders told Western leaders that they could lose control of their jails and redirect guards elsewhere in the case of a Turkish incursion, although they said they would not release foreign fighters willfully.