Obama to take last shot at closing Gitmo

The US military prison in Guantanamo Bay should be shut down before President Barack Obama leaves office, Pentagon chief Ashton Carter said on Thursday, saying the facility was a "rallying cry for jihadi propaganda".

Military officials were actively searching for an alternative detention facility, he said.

"This is not something, in my judgement, that we should leave to the next president," Carter told reporters at the Pentagon.

He said he and the White House were on the same page when it comes to closing the prison - as Obama promised before being elected and which he is now making a final push to accomplish.

"As long as this detention facility remains open, it will remain a rallying cry for jihadi propaganda," Carter said.

"It's expensive... and not something the president wants to leave to his successor."

He said defence officials had been assessing Fort Leavenworth, in Kansas, and the Navy Brig in Charleston, South Carolina as possible destinations for prisoners.

"We will also be assessing other sites in the coming weeks," he added.

Any transfers of the prisoners to sites within the continental US are likely to be highly controversial in Congress, but Carter said his department was working on putting together a concrete plan for lawmakers to consider:

"Our responsibility is to provide [Congress] with a plan that they can consider that is a responsible one so that people... can make up their minds."