Pentagon chief says ‘not confident’ about Guantanamo closure

US President Barack Obama would probably not be able to keep his 2008 campaign promise to shut down the notorious Guantanamo Bay prison by the end of his presidency next year.

In an interview with CBS News on Tuesday, US Secretary of Defense Ashton Carter said he is not confident about the closure of the jail by the time Obama leaves office.

"I'm not confident, but I am hopeful. I think we'll have a good proposal, and I think we're hoping it wins the support that it needs in Congress, so that we can move forward," he said.

The Pentagon is working on a proposal about the closure of the prison to present to Congress and Chairman of the Armed Services Committee Senator John McCain.

Carter said that McCain "said he'd be receptive to considering a proposal of that kind that would allow those people who cannot be released to be placed in a facility in the US, rather than Guantanamo Bay, and then we can close Guantanamo Bay."

The Pentagon chief also noted that all the prisoners should not be released.

“There are people in Guantanamo Bay who cannot and should not be released because they will return to the terrorist fight,” Carter said.

“And therefore we need a place where we can detain them in the long term. We have been forbidden to create such a place in US territory,” he added.

The Guantanamo Bay prison at the US naval base in Cuba was opened in January 2002 to hold terror suspects captured during the so-called war on terror.

There are still dozens of inmates at the prison, where many have been held without a charge or trial.

The US president had promised to close Guantanamo before his election in 2008, citing its damage to the US reputation abroad.

Washington has come under international pressure for using torture, including water-boarding and force-feeding suspects at the prison.