The White House has revealed its plans for closing the controversialGuantanamo Bay detention facility, one of the president's long-standing goals.
The Pentagon has proposed transferring the remaining 91 detainees to their home countries or to US military or civilian prisons.
But Congress is deeply opposed and expected to block the move.
The prison costs $445m (£316m) to run annually and closing it was an early promise from President Barack Obama.
He told reporters on Tuesday the prison undermines national security.
"This is about closing a chapter in our history," said Mr Obama. "It reflects the lessons we've learned since 9/11 - lessons that must guide our nation going forward."
The Pentagon outlined four main components of the plan:
- transfer 35 detainees to foreign countries who have been designated to do so
- do periodic reviews of remaining detainees to see if their detention is still necessary
- continue to use legal tools to deal with remaining detainees
- working with Congress to establish a location in the US to hold detainees who will not go to foreign countries.
The president, who will complete his second and final term in January, said it was important not to pass the problem on to his successor.
"Keeping this facility open is contrary to our values. It undermines our standing in the world. It is viewed as a stain on our broader record of upholding the highest standards of rule of law.''