Dozens of international experts gathered in northeastern Syria on Saturday to discuss how to manage thousands of suspected Islamic State group members crammed into Kurdish-run prisons and camps.
French lawyers and US-based analysts were among those attending the three-day conference on the challenges still facing the region after IS's territorial defeat, organisers said.
Officials of the autonomous Kurdish administration in northeastern Syria, which is hosting the conference in the town of Amuda, were also due to take part.
In March, Kurdish-led fighters overran the last pocket of the jihadists' cross-border "caliphate" with support from a US-led coalition.
Now, the Kurds are struggling to cope with the thousands of alleged IS members they detained during the battle.
They include around 1,000 suspected foreign fighters held in jail, and some 13,000 family members in overcrowded camps.
With no local court equipped to deal with the large number of jihadist suspects, the Kurds have pressed their home countries to take them back.
But Western governments have been reluctant to repatriate them or put them on trial at home.
"There is global consensus that action urgently needs to be taken to deal with the thousands of foreign ISIS fighters and affiliates, plus ISIS-linked children, currently detained in northeast Syria," the organisers of the three-day conference said, using another acronym for IS.
"However, there is near-total lack of consensus as to what this action will look like."
Syria's Kurds have called for outside help to set up an international tribunal.
Iraq has offered to put suspected foreign jihadists on trial in Baghdad in exchange for millions of dollars, officials told AFP in April.