The Pentagon is expected to submit to Congress on Tuesday President Barack Obama's long-awaited plan for closing the U.S. military prison at Guantánamo Bay, setting up a battle with lawmakers who oppose his efforts.

Obama, whose pledge to shut the facility at the U.S. naval base in Cuba dates back to the start of his presidency in 2009, is seeking to make good on his promise before he leaves office next January.

Pentagon spokesman Captain Jeff Davis said the administration intended to meet Tuesday's deadline to present its detailed proposal for closing the facility. There are still 91 prisoners detained there. Of those, 35 are expected to be transferred out by this summer.

White House spokesman Josh Earnest reiterated Obama's view of Guantánamo as a terrorist "recruiting tool" and urged lawmakers to look at the plan "with an open mind," although he expressed doubt about whether they would do so.

The White House has left open the possibility that Obama might resort to executive powers to close the facility.

The plan provides few details, and may only further antagonize members of Congress who have repeatedly passed legislation banning any effort to move detainees to the United States mainland.

Rep. Mac Thornberry, R-Texas, chairman of House Armed Services Committee, has said that his panel would hold a hearing on a closure plan. But he sent a letter to Obama warning that Congress has made clear what details must be included in any plan and that anything less than that would be unacceptable.

U.S. officials say the plan considers 13 different locations in the U.S., including seven existing prison facilities in Colorado, South Carolina and Kansas, as well as six other locations on current military bases. They say the plan doesn't recommend a preferred site and the cost estimates are meant to provide a starting point for a conversation with Congress.

More detailed spending figures, which are considered classified, will be provided to Congress, said the officials, who were not authorized to discuss the plan publicly ahead of its release, so spoke on condition of anonymity.

Members of Congress have been demanding the Guantánamo plan for months, and those representing South Carolina, Kansas and Colorado have voiced opposition to housing the detainees in their states.

The administration is currently prohibited by law from moving Guantánamo Bay detainees to the United States.

Wire services