Turkey said it was in the process of repatriating foreign ex-Islamic State members and fighters to countries where they were citizens before joining the jihadist group in Syria and Iraq. The Turkish Interior Minister Suleyman Soylu recently said Turkey was not a “guest house or hotel” for Islamic State former members and fighters.

Thousands of former Islamic State members are in custody in northern Syria, a predominantly Kurdish area before Turkey’s incursion into the region, after the United States decided to withdraw its troops in early October. But as Turkey advances in its incursion, the Kurdish forces are pushed back from areas they controlled and where thousands of Islamic State ex-members are imprisoned.

Turkey’s recent repatriation wave came after President Erdogan met with President Trump in the White House on Wednesday, November 13. Erdogan said Turkey had thousands of former Islamic State-affiliated individuals in its custody, and that the country was in the process of sending them back to “their countries of origin”.

Two days later, on Friday, November 15, Turkey’s Interior Minister Suleyman Soylu said an American Islamic State suspect had been deported by plane to the United States. “Upon the commitment of the United States to issue a travel document, necessary procedures have been initiated to send the foreign terrorist fighter to the United States,” the Turkish Ministry of Interior declared.

Seven other German nationals were deported to Berlin, the ministry also declared, and one Briton to London.

But if the United State has shown support to Turkey’s aim at deporting former Islamic State-affiliated individuals to countries where they were nationals, some countries in Europe have long objected to taking back those individuals. President Trump, who agreed with President Erdogan that Western countries should take back their Islamic State-affiliated citizens, recently said European nations were a “tremendous disappointment” after they refused to bring back those persons.

Turkey’s state-run news agency Anadolu recently reported that several Europeans countries have reiterated their refusal to take back former Islamic State-affiliated nationals now in Turkish custody. Danish, Irish and French citizens were also due to be deported as part of the repatriation process, the agency also reported.

Turkey said it was intent on sending back those prisoners to their countries even if they were stripped of their citizenship. The United States, where other foreign Islamic State ex-members are detained as well, threatened to deliver those prisoners to their countries nevertheless too.

“I said to them, if you don’t take them back, I’m going to drop them right on your border. And you could have fun capturing them again,” President Trump said in a news conference in late October when he announced the killing of the former leading of Islamic State Abu Bakr al-Baghdadi.

If citizens are presented at their national soil, the international law requires that they be let in. The 1948 Universal Declaration of Human Rights stipulates, “Everyone has the right to leave any country, including his own, and to return to his country.”

The Syrian Democratic Forces, who controlled prisons in northern Syria where thousands of ex-Islamic State members are detained, previously said they had about 800 European fighters in their prisons, as well as 700 women and some 1500 children in camps.

Some European countries said they were willing to take back the women and children, in whom they nevertheless see a political and social threat, but categorically refused to repatriate the fighters and male members. The United States proved less reluctant, analysts said, because it has fewer nationals who were involved with Islamic State.

In anticipation of being called upon to forcibly take those individuals back, some European countries revoked their citizenship after cutting diplomatic ties with Syria amid the war. Those prisoners are then left in a political limbo where Syrian institutions are far from being able to bring them to justice and where conflict still lurks.

Many were said to have escaped the prisons after fights between Kurdish and Turkish forces broke in northeast Syria following Turkey’s incursion on October 9.

After cutting diplomatic ties with Syria and revoking many individuals’ citizenship, countries from Europe say they are not obligated to proactively go into Syria to take those persons back. Some fear that even if brought back to Europe, those prisoners won’t face enough individual-based evidence to be convicted for charges of terrorism.

Many were imprisoned merely for something they had posted on social media or because of the presence of their name in Islamic State documentation.

An idea of establishing an international tribunal to try the prisoners had been brought forth by many actors in the hope of resolving the issue. The Syrian Democratic Forces proposed that the international tribunal be held in territory it controls. Yet it isn’t clear under what international law the prisoners could be tried, as there is no international definition of terrorism, for example. (The Kurdish forces in Syria are considered as a terrorist group by Turkey because of ties they have with the PKK)

US officials said the United States rejected suggestions such as asking countries in the region to detain those former Islamic State members or establishing an international tribunal to try them.

“Each country has a responsibility to handle this situation on their own,” Nathan Sales, the director of the U.S. State Department’s counterterrorism bureau, said. “Our view is that it’s not a viable option to ask other countries in the region to import another country’s foreign fighter and pursue prosecution and incarceration there.”

On Thursday, November 14, a day after Erdogan met Trump, the US Secretary of State Mike Pompeo also stressed on coalition-member European countries to take back their citizens who belonged to Islamic State, in a Global Coalition to Defeat ISIS meeting held in Washington.

“Coalition members must take back the thousands of Foreign terrorist fighters in custody and impose accountability for the atrocities they have perpetrated,” Pompeo said in the meeting.