Obama wants 'fair hearing' on Guantanamo

President Barack Obama has urged politicians to give his plan to close the US military prison at Guantanamo Bay a "fair hearing".

The Pentagon proposal proposes 13 potential sites on US soil for the transfer of remaining detainees, but does not identify the facilities or endorse a specific one, administration officials said on Tuesday.

Obama pledged to close the prison and move the detainees as a candidate for the White House in 2008.

Lawmakers largely oppose moving the prisoners to the United States, however, and his final attempt to get congressional backing is unlikely to gain traction.

"Let us go ahead and close this chapter," Obama said in White House remarks.

"I don't want to pass this problem on to the next president, whoever it is."

Obama leaves office in January 2017.

The Guantanamo prisoners, held at a US naval station in southeastern Cuba, were detained by US troops in Iraq and Afghanistan.

The facility came to symbolise aggressive detention practices in years past that opened the United States to allegations of torture.

The transfer and closure costs would be $US290 million ($A400 million) to $US475 million, an administration official told reporters on a conference call.

Housing remaining detainees in the United States would be $US65 million to $US85 million cheaper than at the Cuba facility, the official said, so costs would be offset in three to five years.

Some 35 prisoners will be transferred from Guantanamo to other countries this year, leaving the final number below 60, officials said.

Obama is considering closing the facility by executive order if lawmakers do not back his proposal.

The plan would send detainees who have been cleared for transfer to their homelands or third countries and transfer remaining prisoners to US soil to be held in maximum-security prisons. Congress has banned such transfers to the United States since 2011.

Though the Pentagon has previously noted some of the sites it surveyed for use as potential US facilities, the administration wants to avoid fuelling any political outcry in important swing states before the November 8 presidential election.