ISTANBUL — Turkey announced on Thursday that it would repatriate an American suspected of being a member of the Islamic State, after a commitment from the United States that his entry would not be blocked.
The American, Muhammad Darwish Bassam, 39, had been stranded on a strip of land at the Turkish-Greek border for the past four days after Turkey had tried to deport him to Greece, but Greek officials refused him entry.
The announcement by the Interior Ministry came a day after President Recep Tayyip Erdogan of Turkey met with President Trump in Washington. Turkey has used Mr. Bassam’s case to highlight its demand that Western countries take back their citizens who joined the Islamic State and have been detained by Turkish forces.
A spokesman at the United States Embassy in Ankara, the Turkish capital, declined to confirm the announcement on privacy grounds.
Little is known of Mr. Bassam or his exact affiliation with the Islamic State. Official news outlets in Turkey have reported that he is of Jordanian origin and holds an American passport. He is reported to have been captured by Turkish-backed forces in northeastern Syria last month, after Mr. Erdogan ordered the seizure of territory to create what he called a safe zone.
Mr. Bassam has been photographed waving his arms and pacing inside the buffer zone between the Turkish and Greek border posts. Journalists were not permitted to speak to him, and a unit of antiterrorism police officers had been guarding him at all times.
Officials from Greece and Turkey have given conflicting statements: Greek officials said that Mr. Bassam had declared that he was being deported against his will to Greece; Turkish officials said that he had requested to go to a third country rather than to the United States.
In an interview with the Turkish daily Sozcu on Wednesday, Interior Minister Suleyman Soylu said that Turkey was holding 2,280 Islamic State members, a far larger number than was previously known.
“There are 2,280 ISIS members in Turkey from 30 countries, all of them will be deported,” Mr. Soylu told the newspaper. He also said that there were 250 Islamic State members in immigration centers in Turkey, 850 who had been captured in the latest operation in northeastern Syria, and 1,180 “being held in Turkish prisons.”
“We’re not a hotel or a guesthouse for terrorists from any country,” he added.
Mr. Bassam’s awkward stay in the stateless zone between Turkey and Greece underscored the daunting challenge of sending captured militants and their family members back to their countries of origin. The United States, Britain and other Western nations have strongly resisted taking back members of the Islamic State, or ISIS, or their wives and children.
There are potentially thousands of people facing this problem, and Turkey has detained hundreds of ISIS members, and a Syrian Kurdish-led militia was holding about 11,000 men and tens of thousands of people, many of them wives and children of fighters.
During Turkey’s recent incursion into Syria, Turkish-allied militias said they had also captured pro-Kurdish fighters. In recent years, several Americans and Europeans had traveled to Syria to fight with the Kurdish-led forces that battled with the United States against the Islamic State.
Turkey considers the Syrian Kurdish militia a terrorist group because of its links to the Kurdistan Workers’ Party, or P.K.K., which has been waging an insurgency inside Turkey for decades. The United States also considers the P.K.K. a terrorist group.