The US has 50 to 60 detainees whom it has been unable to repatriate
At least six of the 13 Chinese Uighur Muslims still held at Guantanamo Bay could soon be transferred to Palau.
The US Solicitor General Elena Kagan told the Supreme Court that the US hoped to move eight of the Uighur by 1 October, and so far six had accepted.
The court is to decide next week if it will consider a plea by several of the Uighur to be resettled on US soil.
The Uighurs, considered separatists by China, have expressed fears that Palau may be too close to China to be safe.
Ms Kagan said six Uighur detainees have agreed to the transfer and attempts to persuade two others are continuing.
Analysts said the US administration was hoping news of the transfers would lessen objections to the Palau move among those still appealing for a US or other alternative.
"The US government has every reason to believe that at least six of the petitioners shortly will be resettled in Palau, although it is impossible to be certain until they actually board the plane," Ms Kagan wrote in a letter to the Supreme Court.
The exact date of departure is classified.
In a separate letter to the court, Sabin Willett, a lawyer representing the Uighurs, said one of the 13, Arkin Mahmud, has not been offered a chance to resettle in Palau, or elsewhere.
Four other Uighur detainees are now in Bermuda and another five went to Albania in 2006.
Palau agreed to a US request to temporarily resettle the Uighurs after the Pentagon determined last year that they were not "enemy combatants".
The tiny Pacific nation does not have diplomatic relations with China.
Instead, it has developed strong ties with Taiwan, which Beijing regards as its renegade province.
The group of 22 Chinese Muslims were captured in Afghanistan and Pakistan in 2001.
The US has said it will not send them back to China for fear they will be tortured or executed.
Beijing demands their handover, saying the detainees are leading an Islamic separatist movement in western China.
Guantanamo Bay officials have been attempting to fulfil US President Barack Obama's order to close the controversial detention facility in Cuba by early next year.
Palau, a former US trust territory, is an archipelago of eight main islands plus more than 250 islets that is best known for diving and tourism and is located some 800km (500 miles) east of the Philippines.
Palau has retained close ties with Washington since independence in 1994 when it signed a Compact of Free Association with the US. It relies heavily on the US for aid and defence.