The United States on Friday defended its treatment of foreign terrorism suspects held abroad, telling a U.N. committee it backed a ban on torture and stressing there had been "relatively few actual cases of abuse."

John Bellinger, the U.S. State Department's top legal adviser, said Washington was "absolutely committed to uphold its national and international obligations to eradicate torture."

Human rights groups this week accused the United States of mistreating detainees through cruel interrogation methods including "water-boarding," a form of mock drowning.

Bellinger, who heads the American delegation to the U.N. Committee Against Torture, said allegations of U.S. abuse had been greatly exaggerated.

"This committee should not lose sight of the fact that these incidents are not systemic," he told the 10-member panel at the start of a two-day review of U.S. compliance with the Convention Against Torture and other Cruel, Inhuman or Degrading Treatment.

"Relatively few actual cases of abuse and wrongdoing have occurred in the context of U.S. armed conflict with al Qaeda," he said.

The United States is holding hundreds of terrorism suspects, most arrested since al Qaeda's September 11 attacks in 2001, at its prisons in Afghanistan, Iraq and Guantanamo Bay, Cuba.

Assistant U.S. Secretary of State Barry Lowenkron told the committee the "notorious" abuses that occurred at Abu Ghraib prison in Iraq "inexcusable and indefensible."

"We know that the image of Abu Ghraib and questions about Guantanamo have been damaging to the reputation of the United States," Bellinger told a news briefing after the session.

"That is one reason the U.S. government is trying very hard to set things on the right course through investigations that have been conducted and through our appearance at the committee today," he said.

CHAIN OF COMMAND

The 10-member U.N. committee grilled the U.S. delegation on whether criminal responsibility has been established for known abuses, and challenged the U.S. definition of torture.

"We would like to have more details regarding the chain of command," said Andreas Mavrommatis, the committee's chairman.

Vice-chairman Wang Xuexian from China asked: "Where would you put such methods as interrogation by mock drownings -- as torture or as other forms of cruel, inhuman or degrading treatment?"

"Are there measures to monitor CIA operations to ensure they are not violating the Convention Against Torture?"

The panel also asked about "extraordinary renditions" whereby prisoners are moved to other countries where, critics say, they can face torture, and asked whether seeking "diplomatic assurances" from governments was enough to prevent abuse of those moved.

"I would like to emphasize that the United States has not transported detainees to countries for purposes of interrogation using torture and will not," Bellinger said in response, adding diplomatic assurances were relied on only "sparingly."

Speaking after the session, Jennifer Daskal of Human Rights Watch decried what she called "a continued attempt by the U.S. to say that the abuse we see in Guantanamo, Iraq and Afghanistan was just limited to a few bad apples."

"The (Bush) administration is unwilling to assume responsibility for policies and practices that were promulgated at a high level, which allow a climate of abuse to flourish," she said.