At a Senate Judiciary Committee hearing, U.S. officials testified the United States has the right to hold foreign detainees as long as the war on terrorism continues.
"I think we can hold them as long as the conflict endures," said Brigadier General Thomas Hemingway, who is with the Defense Department's Office of Military Commissions.
Deputy Attorney General Michael Wiggins put it this way,"It is our position that legally they can be held in perpetuity."
Rear Admiral James McGarrah, who monitors the enemy combatant detention program for the Navy, defended the practice.
"The primary basis for detaining individuals, whether it be at Guantanamo or elsewhere, is their determination as enemy combatant and the authorization under the law of armed conflict and the acceptable laws of war to keep those combatants from returning to the battlefield," he said.
Admiral McGarrah said the Defense Department's annual review of the status of Guantanamo prisoners is "rigorous and fair."
There are more than 500 detainees from some 40 countries at the Guantanamo Bay detention center, which the United States opened in January 2002 in the aftermath of the September 11, 2001 terrorist attacks.
Of the Guantanamo detainees, 12 have been handed over to military commissions for investigation of possible war crimes, and only four have been charged. Many have been held for more than three years.
Many lawmakers and human rights groups have denounced the indefinite detention of prisoners without charge at Guantanamo Bay.
"Try them or release them,? said Senator John McCain, an Arizona Republican. ?I think the key to this is to move the judicial process forward so that these individuals will be brought to trial for any crime that they are accused of rather than residing in the Guantanamo facility in perpetuity."
The chairman of the Judiciary Committee, Senator Arlen Specter, a Pennsylvania Republican, called for better defining the legal rights of terrorism suspects being held at Guantanamo Bay.
"It is a genuine crazy quilt to try to figure out where the due process rights lie. The Supreme Court says there are due process rights," he said.
The Senate hearing was held amid calls from Democratic lawmakers to close the Guantanamo facility, in the aftermath of reports of abuse of detainees by U.S. soldiers and interrogators.
The administration has given mixed signals about the future of the detention center. President Bush last week appeared to leave open the possibility that the facility would be closed. Attorney General Alberto Gonzales, speaking in Brussels, said the administration continues to think about whether or not this is the right approach, the right place, the right manner in which to deal with unlawful combatants.