The U.S. has zeroed in on Singapore as the venue for a historic summit between President Donald Trump and North Korean leader Kim Jong Un, after the return of three U.S. citizens detained in the isolated country removed an obstacle to talks.

Trump is leaning toward holding the meeting in the Southeast Asian city-state, according to an administration official, who asked not to be named as the decision hasn’t been finalized. The president on Wednesday ruled out a meeting in the Korea Peninsula’s Demilitarized Zone, saying he would announce the date and location in the coming days.

The three Korean-American men released by Kim returned to U.S. soil late Wednesday, landing in Anchorage with Secretary of State Mike Pompeo, who brought them back from Pyongyang after talks with the North Korean leader.

Trump praised the North Korean leader for releasing the detained Americans, and the men issued a statement via the State Department thanking Trump and Pompeo for bringing them home. They were seated with medical personnel, curtained off from reporters accompanying Pompeo on a short visit to Pyongyang.

North Korean state media said that Kim granted amnesty to the prisoners after accepting a request from Trump for their release.

At the Kim-Pompeo meeting “an in-depth discussion was made on the practical matters for holding the DPRK-U.S. summit and its procedure and ways,” Kim’s state-run Korean Central News Agency reported. “The respected Supreme Leader exchanged parting words with Mike Pompeo and saw him off, promising to meet again.”

Trump said he intends to meet the freed Americans when they arrive in Washington at about 2 a.m. Thursday. “I appreciate Kim Jong Un doing this and allowing them to go,” Trump said.

CNN reported earlier that U.S. officials have been instructed to proceed with plans to convene the summit in Singapore.

Singapore -- almost 5,000 kilometers (3,000 miles) south of Pyongyang -- represents neutral turf for the two leaders. The city-state of 5.5 million people boasts security partnerships with the U.S., a North Korean embassy and strong ties with China.

Singapore’s government also has a history of putting together high-profile diplomatic events at short notice, notably hosting Chinese President Xi Jinping’s historic 2015 meeting with then Taiwanese counterpart Ma Ying-jeou. Still, Kim’s agreement to travel so far from the safety of Pyongyang -- the farthest he’s ever been as leader -- could be seen as a concession by North Korea, should it happen.