Since campaigning in 2008 on a promise to shutter the controversial detention center, Obama has yet to outline what he will do with the nearly 200 detainees in Cuba, House Armed Services Committee chief Rep. Buck McKeon (R-Calif.) said Friday.
"Most important, that plan needs a proposal for dealing with future terrorist captures," the California Republican said.
Obama should send up a plan to McKeon's committee as they deliberate the Pentagon's fiscal 2014 budget plan over the coming weeks.
"If the president is serious about a renewed effort to close the facility, he should seize the opportunity and send up his plan," McKeon wrote in a separate letter to the editor in The Washington Post on Friday.
But until such a plan is in place, Obama must keep Guantánamo open in the interest of national security, he said.
"The classified nature of [detainee's] offenses permit few the ability to understand the very real danger they pose to our security. But they are dangerous," McKeon wrote in USA Today.
"They do mean us harm. And until a better solution is offered, at Guantanamo they must stay," he added.
On Wednesday, White House press secretary Jay Carney said the administration is exploring options to deport a number of detainees from Gitmo to their home countries.
But those countries have yet to agree to take those individuals back, due to the rules Congress put in place to repatriate those detainees.
"If the certification requirements for transferring foreign terrorists overseas are too stringent, the president needs to tell Congress why and how they should be modified," according to McKeon.
Obama said he would pursue that kind of increased cooperation with Congress on Guantánamo, but with the inherent goal of closing down the prison.
"I'm gonna ask ... some folks [in Congress] ... to step up and help me on it," Obama said last Thursday, pledging to lobby lawmakers on the issue.
Obama called the continued use of the military prison at Guantánamo "contrary" to U.S. interests during last week's press conference at the White House.
"I think it is critical for us to understand that Guantánamo is not necessary to keep America safe," Obama said.
"It is expensive. It is inefficient. ... It lessens cooperation with our allies on counterterrorism efforts," the president added. "It is a recruitment tool for extremists [and] it needs to be closed."
Obama's promise to shut down the prison was a centerpiece of his 2008 campaign, and in his first week in office, he signed an executive order to close the facility. But his efforts have run into fierce opposition from Congress.
Lawmakers have repeatedly attached provisions in military spending bills barring the White House from financing trials of Guantánamo captives. Congress has also mandated military detention for most future terrorism cases, making closure more difficult.