The United States government is in negotiations that could see almost 70 per cent of detainees transferred from Guantanamo Bay to three countries in the Middle East.
A deal has been struck to transfer most of the 110 Afghan terror suspects to the "exclusive custody and control" of the Afghanistan government.
Similar deals are in the pipeline with authorities in Saudi Arabia and Yemen, a Pentagon spokesman said.
Matt Waxman, the deputy assistant secretary of defence for detainee affairs, stressed the plan was not to shut down Guantanamo.
"We don't want to be the world's jailer," he said. "We think a more prudent course is to share responsibility with our coalition partners for keeping these individuals from fighting us again.
"In waging the war against al-Qa'ida and the Taliban we will continue to capture enemy fighters and need to prevent them from returning to the battlefield, but it need not be the US who detains them for the long term."
The US has agreed to help Afghanistan build an appropriate prison and to train its guards.
Pierre-Richard Prosper, the ambassador at large for war crimes, who led a US delegation to the Middle East this week, told The Washington Post the government was working to send 129 Saudis and 107 Yemenis from the prison at a US naval base on Cuba to the custody of their home countries.
The long-term goal is understood to be to reduce the Guantanamo population to those who pose the highest security risk and to shift the focus from intelligence gathering to long-term detention.
Some 510 prisoners are currently being held by the US at the detention camp which has been the subject of much criticism in recent months. The naval base has been the focus of alleged torture and human rights violations and detainees are held and interrogated without charge.
Guantanamo was initially established to hold terror suspects from Afghanistan.
At its peak it held 750 prisoners but more than 100 have been released and 65 dispatched to foreign countries, including seven to Britons who were all later released without charge.Reuse content