Bush was referring to a report on two secret memos in 2005 that authorized extreme interrogation tactics against terror suspects. "This government does not torture people," the president said.

The two Justice Department legal opinions were disclosed in Thursday's editions of The New York Times, which reported that the first 2005 legal opinion authorized the use of head slaps, freezing temperatures and simulated drownings, known as waterboarding, while interrogating terror suspects, and was issued shortly after then-Attorney General Alberto Gonzales took over the Justice Department.

That secret opinion, which explicitly allowed using the painful methods in combination, came months after a December 2004 opinion in which the Justice Department publicly declared torture "abhorrent" and the administration seemed to back away from claiming authority for such practices.

A second Justice opinion was issued later in 2005, just as Congress was working on an anti-torture bill. That opinion declared that none of the CIA's interrogation practices would violate the rules in the legislation banning "cruel, inhuman and degrading" treatment of detainees, The Times said, citing interviews with unnamed current and former officials.

"We stick to U.S. law and international obligations," the president said, without taking questions afterward.

White House and Justice Department press officers have said the 2005 opinions did not reverse the 2004 policy.

Bush, speaking emphatically, noted that "highly trained professionals" conduct any questioning. "And by the way," he said, "we have gotten information from these high-value detainees that have helped protect you."

He also said that the techniques used by the United States "have been fully disclosed to appropriate members of the United States Congress" — an indirect slap at the torrent of criticism that has flowed from the Democratic-controlled Congress since the memos' disclosure.

"The American people expect their government to take action to protect them from further attack," Bush said. "And that's exactly what this government is doing. And that's exactly what we'll continue to do."

The 2005 opinions approved by Gonzales remain in effect despite efforts by Congress and the courts to limit interrogation practices used by the government in response to the Sept. 11, 2001, terrorist attacks. The authorizations came after the withdrawal of an earlier classified Justice opinion, issued in 2002, that had allowed certain aggressive interrogation practices so long as they stopped short of producing pain equivalent to experiencing organ failure or death. That controversial memo was withdrawn in June 2004.

The dispute may come down to how the Bush administration defines torture, or whether it allowed U.S. interrogators to interpret anti-torture laws beyond legal limits. CIA spokesman George Little said the agency sought guidance from the Bush administration and Congress to make sure its program to detain and interrogate terror suspects followed U.S. law.

Senate and House Democrats have demanded to see the memos.

"Why should the public have confidence that the program is either legal or in the best interests of the United States?" Senate Intelligence Committee Chairman Jay Rockefeller, D-W.Va., wrote in a letter to the acting attorney general.

House Judiciary Chairman John Conyers and Rep. Jerrold Nadler, D-N.Y., promised a congressional inquiry.

Sen. John McCain, R-Ariz., said he was "personally assured by administration officials that at least one of the techniques allegedly used in the past, waterboarding, was prohibited under the new law."

A White House spokesman, meanwhile, criticized the leak of such information to the news media and questioned the motivations of those who do so.

"It's troubling," Tony Fratto said Friday. "I've had the awful responsibility to have to work with The New York Times and other news organizations on stories that involve the release of classified information. And I can tell you that every time I've dealt with any of these stories, I have felt that we have chipped away at the safety and security of America with the publication of this kind of information."

"It's embarrassing for the Senate. It's embarrassing for our party," said Sen. John Ensign of Nevada, who leads the GOP's Senate campaign committee.

"I think it's best for the U.S. Senate, it's best for certainly his party, that he just keeps his word," Ensign told reporters outside the Senate chamber Thursday. "He gave us his word he would do something, and he's backing out on us, and I don't think that's the right thing to do."

A judge ruled Thursday that Craig's guilty plea to a misdemeanor disorderly conduct charge could not be withdrawn. Craig entered the plea after his June arrest in a men's room at the Minneapolis-St. Paul International Airport for allegedly propositioning a plainclothes police officer for sex.

After news of his arrest and guilty plea broke in August, the senator announced that he would resign at the end of September, but he postponed that move while seeking to have his guilty plea withdrawn.

However, after the judge's ruling Thursday, Craig said he'll remain in the Senate and study "additional legal options" -- much to the consternation of some GOP colleagues. Watch how Craig's decision poses a challenge for GOP leaders »

Sen. John Thune, R-South Dakota, called the issue "a distraction" for the party.

"I would have hoped he would have done what he said he was going to do," added Sen. Norm Coleman, R-Minnesota.

"He's chosen not to. The people of Idaho will have to speak to that, and the Ethics Committee will have to speak to that," Coleman said, referring to the Senate panel's indication that it will investigate Craig's conduct.

Fellow Idahoan Sen. Mike Crapo was a rare voice in the caucus, issuing a statement in support of Craig's decision.

"I look forward to serving with him as we continue to work on issues important to Idaho," Crapo said.

But in Boise, a spokesman for Idaho Gov. C.L. "Butch" Otter said that the Republican governor already has settled on a replacement for Craig -- but won't name the choice until the senator steps down.

Spokesman Jon Hanian denied that Otter, a longtime friend, is pushing Craig to go, saying the governor "just wants to be ready."

A Craig resignation would give an appointee the advantage of being in office for a year or more before the next election. Craig said he won't seek re-election in 2008, a decision advisers said he had made earlier.

The lack of an Idaho incumbent -- if that happens -- would complicate things for the GOP in what already is shaping up to be a difficult 2008 election.

Four other Republican senators -- John Warner of Virginia, Chuck Hagel of Nebraska, Wayne Allard of Colorado and Pete Domenici of New Mexico -- have announced they will not seek re-election, and at least four others are expected to face tough races.

"Democrats are cheering today," the Idaho Statesman newspaper said in an editorial urging Craig to go ahead and resign.

"He and we will be distracted by a Senate Ethics Committee and its hearings, which could be public, in what is certain to be brutally ugly, possibly on live TV, and centered on men having sex with men," the editorial warned.

Jasper LiCalzi, a political science professor at Albertson College of Idaho, told the Idaho Statesman that some voters still back Craig.

"There is core support here that thinks Craig has been railroaded, and there's another group that thinks he should stick it out," LiCalzi told the newspaper.

In his statement Thursday, Craig said any replacement would lack the seniority and committee assignments "that are valuable to Idaho." In addition, he said he wanted to clear his name before the Senate Ethics Committee.

One of Craig's attorneys, Stanley Brand, said on NBC's "Today" show Friday that Craig is considering appealing the judge's ruling and seems willing to risk a Ethics Committee inquiry.

"What he is saying is in 220 years of recorded history ... the Senate has never disciplined anyone for misdemeanor conduct that has nothing to do with official duties," Brand said on "Today." "So, while the Senate theoretically could do that, it hasn't, and our position is there is no reason to start now after 220 years."