Vice President Dick Cheney, meanwhile, said "it's a good thing" that top al-Qaida leaders who underwent the harsh interrogation tactic in 2002 and 2003 were forced to give up information that helped protect the country.
"It's a good thing we had them in custody, and it's a good thing we found out what they knew," Cheney told the Conservative Political Action Conference in Washington.
Since the Sept. 11, 2001, terror attacks, President Bush has "made the right decisions for the right reasons," Cheney said. "And would I support those same decisions again today? You're damn right I would."
Waterboarding involves strapping a person down and pouring water over his or her cloth-covered face to create the sensation of drowning. It has been traced back hundreds of years, to the Spanish Inquisition, and is condemned by nations around the world. Critics call it a form of torture.
This week, for the first time, the Bush administration acknowledged it waterboarded al-Qaida detainees Khalid Sheikh Mohammed, Abu Zubaydah and Abd al-Rahim al-Nashiri. CIA Director Michael Hayden on Thursday said waterboarding was used, in part, because of widespread belief among U.S. intelligence officials that more catastrophic attacks were imminent.
In 2006, the CIA banned waterboarding by its personnel in the wake of a Supreme Court decision and new laws on the treatment of U.S. detainees.
"It is not included in the current program, and in my own view, the view of my lawyers and the Department of Justice, it is not certain that that technique would be considered to be lawful under current statute," Hayden told the House Intelligence Committee.
Hours earlier, Attorney General Michael Mukasey pushed back against Democrats on the House Judiciary Committee demanding to know whether he would prosecute U.S. interrogators who used waterboarding in the past.
"Are you ready to start a criminal investigation into whether this confirmed use of waterboarding by U.S. agents was illegal?" the committee's chairman, Rep. John Conyers, D-Mich., asked, calling the technique an "odious practice."
"No, I am not," Mukasey answered bluntly.
He said the Justice Department could not investigate or prosecute people for actions that it had authorized earlier.
Mukasey has refused to say publicly whether he considers waterboarding legal. On Thursday he said it "was found to be permissible under the law as it existed" in the years immediately following 9/11.
Critics say waterboarding violates the U.N. Convention Against Torture and U.S. laws outlining legal treatment of detainees. The Justice Department long has resisted exposing the Bush administration and its employees to criminal or civil charges or even international war crimes if waterboarding were declared illegal.
Larry Cox, executive director of Amnesty International USA, called Thursday's testimony an example of "the gold standard of double standards."
"Everyone in the world knows that waterboarding is torture and illegal," Cox said. "The U.S. government admits having done it.
Yet the highest law enforcement official in the land refuses to investigate this scandal."
The White House this week said waterboarding still could be legal in interrogating future terrorism suspects in some situations, as long as Bush authorizes it after consulting with the attorney general and intelligence officials.
The House Judiciary Committee's top Republican, Rep. Lamar Smith of Texas, said he hoped the "administration will not be defensive about using some admittedly harsh but non-lethal interrogation techniques."
"Would you agree with me that 99 percent of the American people would probably endorse such techniques if they would be shown to save thousands of American lives and were conducted only on terrorists?" Smith asked Mukasey.
"I can't sit here and say what I think 99 percent of people would do," Mukasey answered.
"You can't but I can," Smith said. "I understand that."
Former military and intelligence officials who have spoken out against waterboarding say the refusal by the United States to outlaw the technique could prompt terrorists or enemy nations to use it on U.S. personnel who may be detained in the future.
"Under what circumstances would it ever be permissible under international law for a foreign nation to interrogate a U.S. citizen by strapping a U.S. citizen to a board and suffocating him or her with water with the intent to create the fear of death?" Rep. Hank Johnson, D-Ga., asked Mukasey.
The attorney general, who earlier refused to say whether he considers the rack or thumbscrews forms of torture, said he would not answer a hypothetical situation.
"Because to do so would indicate the contours of what may or may not be permitted under a program that is classified," he said.
