The Kurdish-led administration in northern Syria has called for the creation of an international court to try thousands of suspected members of the Islamic State (IS) group.
One official, Abdul Karim Omar, told the BBC they were struggling to cope with the thousands who emerged from the last IS enclave of Baghuz, in the east.
Kurdish-led Syrian Democratic Forces (SDF) captured the village last week.
About 1,000 foreign fighters are among the thousands held by Kurds in camps.
US President Donald Trump hailed the capture of Baghuz last week, although he said the US would “remain vigilant” as the group remains a threat.
At its height, IS controlled 88,000 sq km (34,000 sq miles) across Syria and Iraq.
While it no longer holds this territory, US officials believe IS may have 15,000 to 20,000 armed adherents active in the region, many of them in sleeper cells, and that it will return to its insurgent roots while attempting to rebuild.
In a statement, the Kurdish administration called for “a special international tribunal in north-east Syria to prosecute terrorists” to ensure that trials are “conducted fairly and in accordance with international law and human rights covenants and charters”.
Speaking to the BBC, the administration’s head of foreign affairs, Abdul Karim Omar, said the fact so few nations had repatriated their citizens who joined IS has added to their problems.
The administration has struggled to cope with even detaining the militants it has captured, let alone putting them on trial, says the BBC’s Aleem Maqbool in Syria.
Many Western governments have refused to repatriate their citizens amid concerns over the potential security risks they may pose, as well as the challenges of gathering evidence to support prosecutions.