US officials said the Pentagon has notified Congress of its intent to transfer six Guantanamo Bay, Cuba, detainees to Uruguay.
Uruguayan President Jose Mujica has opposed the way detainees are treated at Guantanamo and has said that he would take them in, but then they would be free to leave.
The officials, who spoke on Wednesday on condition of anonymity because it is the administration's policy not to publicly confirm such notifications, said the Pentagon alerted Congress of the plan last week. In practice, the actual transfer would not take place until at least 30 days after the congressional notification.
It would be the first transfer of Guantanamo Bay detainees since five former Taliban commanders were exchanged in May for Bowe Bergdahl, the Army sergeant who had been held for five years by the Taliban. The release of the five for Bergdahl irritated Congress because it was not given the required 30-day notice.
There currently are 149 Guantanamo detainees.
The New York Times, which first reported the plan to release the six detainees, reported that the group includes four Syrians, one Palestinian and one Tunisian.
US and Uruguayan officials have spoken publicly in recent months about their negotiations over terms under which Uruguay would allow a number of Guantanamo Bay prisoners to resettle there. It is not clear what Uruguay would gain, beyond advancing the cause of eventually closing Guarantamo Bay.
Numerous Latin American leaders have been critical of the US detention centre.
Mujica told The Associated Press on May 2 that he wanted to help close Guantanamo Bay by taking some prisoners but would not agree to Washington's demand to keep the former terror suspects inside Uruguay.
"They will be able to move freely," he said. "They can leave. But they've been turned into walking skeletons. They've been destroyed by what they've gone through, physically and psychologically." He declined to say more to avoid complicating the talks. "We've made our proposal. It's the United States that has to decide."
Mujica met with President Barack Obama at the White House on May 12. In their public remarks neither leader mentioned a Guantanamo Bay prisoner deal.