About 200 of the detainees have filed petitions in federal court challenging their captivity.
Over recent days, administration officials have given mixed signals about Guantanamo's future.
Attorney General Alberto Gonzales, on a trip to Europe, defended the prison camp yesterday but added, "We have been thinking about, and continue to think about, whether or not this is the right approach, is this the right place, is this the right manner to deal with unlawful combatants."
Sen. Lindsey Graham (R., S.C.), a former Air Force lawyer and a member of the Judiciary Committee, said it was urgent for the Bush administration and Congress to "help define what's going on in Guantanamo and better define what an enemy combatant is."
The administration decided soon after the Sept. 11, 2001, attacks to hold hundreds of prisoners from Afghanistan and elsewhere as unlawful enemy combatants - suspected terrorists who do not deserve Geneva Convention protections.
Legal battles stemming from the executive branch's decisions have played out in the federal courts for three years without a resolution. Congress has never used its constitutional authority to set the rules for detentions and interrogations.
That must change, Graham warned. "Because if we don't have the buy-in across the country and all three branches of government [on Guantanamo], we're going to lose this war if we don't watch it," he said.
Endangering troops?
In the last week, other Republican senators - Mel Martinez of Florida and Chuck Hagel of Nebraska - said they were troubled by the prospect of long detentions at Guantanamo with no resolution in sight.
