WASHINGTON (AP) – The Bush administration, called to account by Congress after the Supreme Court blocked military tribunals, said Tuesday all detainees at Guantanamo Bay and in U.S. military custody everywhere are entitled to protections under the Geneva Conventions.

White House spokesman Tony Snow said the policy, outlined in a new Defense Department memo, reflects the recent 5-3 Supreme Court decision blocking military tribunals set up by President Bush. That decision struck down the tribunals because they did not obey international law and had not been authorized by Congress.

The policy, described in a memo by Deputy Defense Secretary Gordon England, appears to change the administration’s earlier insistence that the detainees are not prisoners of war and thus not subject to the Geneva protections.

The memo instructs recipients to ensure that all Defense Department policies, practices and directives comply with Article 3 of the Geneva Conventions governing the humane treatment of prisoners.

“You will ensure that all DOD personnel adhere to these standards,” England wrote.

The memo was first reported by the Financial Times, a British newspaper, and was later distributed to reporters at the Pentagon.

Word of the Bush administration’s new stance came as the Senate Judiciary Committee opened hearings Tuesday on the politically charged issue of how detainees should be tried.

“We’re not going to give the Department of Defense a blank check,” Republican Sen. Arlen Specter of Pennsylvania, the committee chairman, told the hearing.

Sen. Patrick Leahy of Vermont, the committee’s top Democrat, said “kangaroo court procedures” must be changed and any military commissions “should not be set up as a sham. They should be consistent with a high standard of American justice, worth protecting.”

The Senate is expected to take up legislation addressing the legal rights of suspected terrorists after the August recess _ timing that would push the issue squarely into the election season.

Guantanamo has been a flash point for both U.S. and international debate over the treatment of detainees without trial and over allegations of torture, denied by U.S. officials. Even U.S. allies in the war on terrorism have criticized the facility and process.

The camp came under worldwide condemnation after it opened more than four years ago, when pictures showed prisoners kneeling, shackled and being herded into wire cages. It intensified with reports of heavy-handed interrogations, hunger strikes and suicides.

Snow insisted that all U.S. detainees have been treated humanely. Still, he said, “We want to get it right.”

“It’s not really a reversal of policy,” Snow asserted, calling the Supreme Court decision “complex.”

Steven Bradbury, acting assistant attorney general of the Justice Department’s Office of Legal Counsel, told the Senate hearing that the Bush administration would abide by the Supreme Court’s ruling that a provision of the Geneva Conventions applies.

But he acknowledged that the provision _ which requires humane treatment of captured combatants and requires trials with judicial guarantees “recognized as indispensable by civilized people” _ is ambiguous and would be hard to interpret.

“The application of common Article 3 will create a degree of uncertainty for those who fight to defend us from terrorist attack,” Bradbury said.

Snow said efforts to spell out more clearly the rights of detainees does not change the president’s determination to work with Congress to enable the administration to proceed with the military tribunals, or commissions. The goal is “to find a way to properly do this in a way consistent with national security,” Snow said.

Snow said that the instruction manuals used by the Department of Defense already comply with the humane-treatment provisions of Article 3 of the Geneva Conventions. They are currently being updated to reflect legislation passed by Congress and sponsored by Sen. John McCain, R-Ariz., to more expressly rule out torture.

“The administration intends to work with Congress,” Snow said.

“We want to fulfill the mandates of justice, making sure we find a way properly to try people who have been plucked off the battlefields who are not combatants in the traditional sense,” he said.

“The Supreme Court pretty much said it’s over to you guys (the administration and Congress) to figure out how to do this. And that is where this is headed.”

Under questioning from the committee, Daniel Dell’Orto, principal deputy general counsel at the Pentagon, said he believes the current treatment of detainees _ as well as the existing tribunal process _ already complies with Article 3 of the Geneva Conventions.

“The memo that went out, it doesn’t indicate a shift in policy,” he said. “It just announces the decision of the court.”

“The military commission set up does provide a right to counsel, a trained military defense counsel and the right to private counsel of the detainee’s choice,” Dell’Orto said. “We see no reason to change that in legislation.”