U.N. human rights investigators criticized the United States on Thursday for failing to take steps to close the Guantanamo Bay military prison for terror suspects, which they say facilitates torture and violates international law.

In the first U.N.-sanctioned inquiry into U.S. practices at Guantanamo, the rights experts also criticized the Bush administration for a proposed law they said might permit torture in certain circumstances.

The experts presented their report on Guantanamo and its 450 detainees to the 47-nation U.N. Human Rights Council, a summary of which was released earlier this year.

"We note with the greatest concern that the government has not taken any steps to close Guantanamo," the rights experts said in a joint statement read by Algerian Leila Zerrougui, a specialist on arbitrary detention. "Indeed, a new block has been built and is set to open this month."

The United States responded by saying it would like to one day close Guantanamo, but first needs to find alternative means of protection from suspected terrorists. It criticized the allegations as poorly founded and said detainees are treated humanely.

The experts criticized President Bush's proposal on a new law regarding how to treat dangerous terrorism subjects, saying it failed to uphold the absolute prohibition on torture and "might permit abuses depending on the circumstances."

Zerrougui said the proposed bill would ensure that detainees are still denied minimum standards for fair trials.

Warren W. Tichenor, the U.S. ambassador to the U.N. in Geneva, criticized the experts for asserting "without real evidentiary support, conclusions they had clearly already reached."

"There is little indication that they considered seriously the voluminous information provided in writing by the U.S. government," Tichenor told the council, of which the United States is only an observer. "By contrast, the report treats second- and third-hand allegations from press reports and contacts with attorneys for the detainees as true."

The panel had sought access to Guantanamo Bay since 2002, but refused a U.S. offer for three experts to visit the camp in November after being told they could not interview detainees. They launched their investigation regardless after saying they had reliable accounts that suspected terror detainees being held there have been tortured.

The Red Cross said Wednesday its representatives will travel to Guantanamo to visit 14 high-level detainees connected to the Sept. 11 attacks, the USS Cole bombing or the 1998 bombings of the U.S. embassies in Kenya and Tanzania.

The detainees — recently transferred from CIA custody to Guantanamo — will be made available to the Red Cross around Oct. 1, U.S. military officials said.