President Bush said Thursday that he expects U.S. authorities to follow the law when interrogating prisoners abroad, but he declined to say whether he believes torture is permitted under the law.

Pressed repeatedly during a news conference here about a Justice Department memo saying torture could be justified in the war on terrorism, Bush said only that U.S. interrogators had to follow the law.

Asked whether he agrees with the Justice Department view, Bush said he could not remember whether he had seen the memorandum. "The authorization I issued was that anything we did would conform to U.S. law and would be consistent with international treaty obligations," he said.

A second questioner asked Bush whether he would authorize "any means necessary" to elicit information from a prisoner who had information about an imminent terrorist attack. The president replied: "What I've authorized is that we stay within U.S. law."

Pointing out that the administration lawyers who wrote the memo believe terrorist suspects could be tortured without violating the law, a third questioner asked whether torture is ever morally justified. "Look, I'm going to say it one more time," Bush replied. "Maybe I can be more clear. The instructions went out to our people to adhere to law. That ought to comfort you."

An Aug. 1, 2002, Justice Department memo from the Office of Legal Counsel to White House counsel Alberto R. Gonzales, says torturing suspected al Qaeda members abroad "may be justified" and that international laws against torture "may be unconstitutional." The Defense Department used the Justice memo in crafting a similar March 2003 memo.

The administration is redefining the law as it has been commonly understood, according to senior civilian and military lawyers aware of the Justice Department's interpretation of torture and who asked to remain unnamed.

"They have reinterpreted it to the point that they are meaningless terms," said Kenneth Roth, executive director of Human Rights Watch.

In particular, the Justice Department defined torture in a much narrower way than has been the general standard to date, making "within U.S. law" a definition that might not be accepted elsewhere. For example, torture must be equivalent to such serious injury to cause "organ failure, impairment of bodily function, or even death."

But the Justice Department also concludes that the torture convention, an international law prohibiting torture, does not expressly prohibit cruel and inhumane treatment, which would include a wide range of painful acts that fall short of "serious physical injury such as organ failure, impairment of bodily function, or even death."

"We conclude that the treaty's text prohibits only the most extreme acts by reserving criminal penalties solely for torture and declining to require such penalties for 'cruel, inhuman, or degrading treatment or punishment,' " the department memo said.

The Justice Department said this conclusion was based on the examination of cases brought against individuals under the Torture Victims Protection Act and international legal decisions regarding the use of sensory deprivation techniques.

"These cases make clear," the Justice Department said, "that while many of these techniques may amount to cruel, inhuman or degrading treatment, they do not produce pain or suffering of the necessary intensity to meet the definition of torture. From these decisions, we conclude that there is a wide range of such techniques that will not rise to the level of torture."

The memo concludes that if U.S. personnel were to be accused or charged with violating the torture convention, "under the circumstances of the current war against Al Qaeda and its allies, application of Section 2340A (the Convention on Torture) interrogations undertaken pursuant to the President's Commander-in-Chief powers may be unconstitutional."

Finally, "even if an interrogation method might violate Section 2340A, necessity or self-defense could provide justifications that would eliminate criminal liability," the 50-page memo concludes. Therefore, an individual accused of torture could still be acting within U.S. law.

The memo was written to give the CIA guidance and legal protection from civil and criminal prosecution, and to help the agency push the limit on what would be acceptable, harsh techniques that the U.S. government would not consider torture.

Minutes after Bush spoke, the administration's view on prisoner interrogation was criticized by French President Jacques Chirac, who has been a constant irritant to Bush. "Yes, we should fight terrorism, but we should not forget the principles on which our civilization rests, such as human rights," Chirac said at a news conference.

Priest reported from Washington. Staff writer Glenn Kessler in Georgia contributed to this report.