Trump threatens to release IS foreign fighters unless Europe takes them back
It comes as the US-backed Syrian Democratic Forces launch a final battle against the jihadi group, who now control just a tiny patch of land in eastern Syria.
With foreign fighters and civilians now being held by the SDF, Trump has told European countries that they must take back their citizens who moved to IS' self-declared "caliphate" since it was established in 2014.
"The United States is asking Britain, France, Germany and other European allies to take back over 800 [IS] fighters that we captured in Syria and put them on trial," Trump said in a tweet.
"The Caliphate is ready to fall. The alternative is not a good one in that we will be forced to release them. The US does not want to watch as these [IS] fighters permeate Europe, which is where they are expected to go."Security experts have feared that IS foreign fighters might have fled the last scraps of land held by the jihadis and crossed the border into Turkey to travel back to Europe.
Intelligence chiefs have also warned that IS sleeper cells are likely active and ready to launch attacks on civilian targets in Syria and Europe.
Hundreds of people from France, Belgium, the UK, Germany and other countries have fought for IS or headed to its territories in Syria and Iraq since the group's ascendency in 2014.
European countries have said they do not want them back, although there could be legal implications with this.
The case of Shamima Begum, a British woman who moved to IS-occupied Syria when she was a schoolgirl, has brought the issue of what to do with citizens who want to return home - particularly minors.
The US has said it will assist with repatriation and are due to pull its 2,000 troops out of Syria with the defeat of IS just hours away.
"We do so much, and spend so much - Time for others to step up and do the job that they are so capable of doing. We are pulling back after 100% Caliphate victory!" Trump said in a late-Saturday tweets. A French government source criticised Trump's demand that Europe take back foreign fighters.
"We're leaving, you're staying," he said, regarding Trump's decision to pull US troops out of Syria by April.
"They're trying to manage the consequences of a hasty decision and making us carry the responsibility."
Agencies contributed to this story.