WASHINGTON — The White House said Wednesday that the widely condemned interrogation technique known as "waterboarding" is legal and that President Bush could authorize the CIA to resume using the simulated drowning method under extraordinary circumstances.

The surprise assertion from the Bush administration reopened a debate that many in Washington had considered closed. Two laws passed by Congress in recent years — as well as a Supreme Court ruling on the treatment of detainees — were widely interpreted to have banned the CIA's use of the extreme interrogation method.

But in remarks that were greeted with disbelief by some members of Congress and human rights groups, White House spokesman Tony Fratto said waterboarding was a legal technique that could be employed again "under certain circumstances."

Fratto said the nation's top intelligence officials "didn't rule anything out" during congressional testimony Wednesday on CIA interrogation methods, and indicated that Bush might consider reauthorizing waterboarding or other harsh techniques in extreme cases, such as when there is "belief that an attack might be imminent."

For years, White House officials denied that the U.S. had engaged in torture but always stopped short of confirming whether waterboarding had been used. The administration's latest stance — described by Fratto during the daily White House briefing — was denounced Wednesday by key lawmakers. "This is a black mark on the United States," said Sen. Dianne Feinstein, D-Calif., a member of the Senate Intelligence Committee. "The White House is trying to give themselves as much of an open field here as possible. It says to others that we are prepared to use the same kinds of tactics used by the most repressive regimes and the most heinous regimes."

The White House comments came one day after CIA Director Michael V. Hayden testified publicly for the first time that the agency had used waterboarding on al-Qaida suspects in 2002 and 2003. He also identified three prisoners, including self-proclaimed Sept. 11 mastermind Khalid Sheikh Mohammed, who he said were the only detainees subjected to the method.

Waterboarding refers to a practice that involves strapping down a prisoner and dousing him with water to simulate the sensation of drowning. The technique has been traced back to the Spanish Inquisition, and has been the subject of war crimes trials dating back a century.

The White House position on the issue is in some ways consistent with its long-standing efforts to expand executive power and resist attempts by Congress to rein in the president's authority.
Still, the decision to reignite the debate over waterboarding struck many in Washington at least as peculiar. The White House had previously argued that any discussion of CIA interrogation methods would only aid the enemy. Further, the CIA halted its use of waterboarding nearly five years ago. Calling renewed attention to the issue risks drawing new criticism from other countries at a time when the United States is seeking to shore up it image abroad.

The issue has also been divisive politically for Republicans. U.S. Sen. John McCain of Arizona, now the front-runner for the GOP nomination for president, has led efforts to outlaw waterboarding and other harsh interrogation methods previously employed by the CIA.

In a recent GOP presidential debate, McCain said it was inconceivable that "anyone could believe that (waterboarding is) not torture. It's in violation of the Geneva Convention. It's in violation of existing law."

The leading Democratic contenders for the White House, U.S. Sens. Hillary Rodham Clinton of New York and Barack Obama of Illinois, have taken similar positions.