Obama 'not ready to concede' Guantanamo will stay open
US President Barack Obama holds a press conference following the conclusion of the Association of Southeast Asian Nations (ASEAN) summit in Laos on September 8, 2016 (AFP Photo/Saul Loeb)

With months left in office, US President Barack Obama said Thursday he was not ready to give up on an eight-year-old promise to close the prison at Guantanamo Bay.

Obama urgently wants to shutter the facility before he leaves the White House at the start of next year but his efforts have been continually thwarted by Republican lawmakers.

"I am not ready to concede that it may still remain open, because we're still working diligently to continue to shrink the population," Obama said at a press conference in Laos.

Speaking in the capital Vientiane during the final trip to east Asia of his eight-year presidency, Obama said the controversial prison served as a "recruitment tool" for terrorist organisations and was a waste of money.

"As we continue to shrink the population to the point where we're looking at 40 or 50 people and are maintaining a multimillion dollar operation to house these people, the American people are asking why should we spend this money on this when it could be spent on other things," he told reporters.

In recent months the US has accelerated the rate at which detainees who have been approved for transfer are released from the US military-run facility, which sits on a remote chunk of land on the tip of southeastern Cuba.

In August, fifteen Guantanamo Bay detainees were transferred to the United Arab Emirates, the largest such release in years.

That batch included 12 Yemenis, who the Pentagon had struggled relocate to a third country as they can't go home because of the ongoing civil war.

Afghan national Obaidullah who had been detained for 14 years without trial was also released with that group.

Roughly 780 men have passed through the facility since it was opened in the wake of the 9/11 attacks to hold terror suspects.

The population now stands at 61, down from 242 when Obama took office in January 2009.

Obama wants to send the remaining inmates, who are deemed to be the most dangerous, for incarceration in the US -- but that is an extreme long shot given Republican opposition.

In February, the president presented Congress with a new closure plan for Guantanamo but Republicans resisted.

November's election will likely help determine the future of the notorious prison, as Republican presidential candidate Donald Trump has vowed to fill Guantanamo with "bad dudes" should he win the White House.

To date, just 10 of the remaining detainees face criminal trial, including the "9/11 Five" -- led by Khalid Sheikh Mohammed -- who are accused of plotting the September 11, 2001 attacks.

Former inmates who are transferred are usually freed subject to supervision and undergoing rehabilitation programmes.