US President Barack Obama vows to 'do everything I can' to close Guantanamo

US president Barack Obama said in a TV interview set for broadcast on Sunday that he will do "everything I can" to close the US military prison at Guantanamo Bay, Cuba, after four Afghan detainees held there were sent home.

Obama promised to shut the internationally condemned prison when he took office nearly six years ago, saying it was damaging America's image around the world. But he has been unable to do so, partly because of obstacles posed by the US Congress.

"I'm going to be doing everything I can to close it," Obama said on CNN's "State of the Union with Candy Crowley," program in an interview taped on Friday.

"It is something that continues to inspire jihadists and extremists around the world, the fact that these folks are being held," he said.

"It is contrary to our values and it is wildly expensive. We're spending millions for each individual there. And we have drawn down the population there significantly," he added.

In the latest step in the gradual push to close the prison, four Afghans held for over a decade at Guantanamo have been sent home, the Pentagon said on Saturday.