WASHINGTON, Dec 31: The US Justice Department has revised its definition of acts that constitute torture, repudiating an earlier definition that human rights activists say led to the abuse of prisoners in Iraq , Afghanistan and Guantanamo Bay.

In a statement issued on Thursday, the department declared: "Torture is abhorrent both to American law and values and international norms." The statement also cancelled a previous definition that said only "organ failure, impairment of bodily function, or even death" constitute torture punishable by law.

The new memo quotes acting Assistant Attorney General Daniel Levin as saying that torture may consist of acts that fall short of provoking excruciating and agonizing pain and thus may include mere physical suffering or lasting mental anguish.

Human rights groups interpreted the new definition as an endorsement of their view that those who conduct harmful interrogations cannot be exempted from prosecution, as they were under the previous US definition of torture.

The first memo, drafted in August 2002 by White House counsel and President Bush's nominee for attorney general Alberto R. Gonzales, was criticized by human rights lawyers and experts around the world.

The critics charged that the first memo laid out a very narrow view of what behaviour might constitute torture and was crafted to help interrogators at the CIA evade prosecution.

The earlier definition, the critics said, created the context for a record of persistent ill treatment by that CIA and the US military of detainees at prisons in Iraq, Afghanistan, Cuba's Guantanamo Bay and other locations.

One of the most controversial provisions of the earlier memorandum was an assertion that the president's executive powers were sufficient to permit tolerance of torturous acts in extraordinary circumstances.

Groups such as the International Committee of the Red Cross had rejected this assertion saying that the prohibition on torture, embodied in a global convention signed by the United States, has no exceptions.

The new memo pointedly side steps this issue, stating that the "consideration of the bounds of any such authority would be inconsistent with the president's unequivocal directive that United States personnel not engage in torture."

The memo, which states that it "supersedes the August 2002 memorandum in its entirety," also drops an attempt in the earlier version to rule that harmful acts not specifically intended to cause severe pain and suffering might be legal, and to define "specific intent."