White House defends Guantanamo releases

The White House has defended the release of five Guantanamo detainees in exchange for a US soldier held by the Taliban, saying a potential threat had been "sufficiently mitigated."

Army Sergeant Bowe Bergdahl - the only US soldier held by the Taliban after being captured in Afghanistan - was freed on Saturday in a dramatic deal brokered by Qatar.

In exchange, five Taliban prisoners were turned over to the Arab emirate, where they will remain for a year, sparking criticism from some Republicans, who claimed they could return to the battlefield and pose a threat to Americans abroad.

But White House Press Secretary Jay Carney took to the US morning talk shows on Monday to downplay the threat posed by the men - influential former officials of the Taliban regime that was toppled by the US-led invasion of Afghanistan.

"We have a history in this country of making sure that our prisoners of war are returned to us, we don't leave them behind," Carney told CNN.

"And it's entirely appropriate, given the determination made by the secretary of defence, in consultation with the full national security team, that the threat potentially posed by the returned detainees was sufficiently mitigated to allow us to move forward and get Bowe Bergdahl back home where he belongs."

Carney added that a travel ban and monitoring was in effect, giving Pentagon chief Chuck Hagel "the confidence to make the determination he did.

"I can say that we do believe and have confidence that the measures put in place in agreement with the host country allow us to feel confident that the threat is sufficiently mitigated," he said.

Bergdahl's almost five years in captivity saw him transferred between various militant factions along the volatile Afghanistan-Pakistan border, finally ending up in Pakistan's North Waziristan tribal district, according to militant sources.

The circumstances of the Idaho native's disappearance, from a base in Afghanistan's eastern Paktika province in 2009, remain unclear.

He arrived Sunday at the US military medical centre in Landstuhl in southern Germany where he is to continue his "reintegration process," the army said.