The United States was urged to completely abolish the CIA's secret detention of terrorism suspects, according to UN High Commissioner for Human Rights Louise Arbour on Friday.

U.S. President George W. Bush acknowledged the existence of CIA secret prisons on Wednesday, and announced that 14 prisoners had been transferred to Guantanamo Bay in Cuba, where a U.S. naval base is located.

Arbour had learned about Washington's announcement and viewed it as "significant," her spokesman Jose Luis Diza told reporters in a regular briefing.

But the high commissioner also "urges that the program of secret detention be completely abolished," Diaz said. "The system should be done away with."

Among the 14 prisoner transferees were the suspected mastermind of the September 11 attacks, Khalid Sheik Mohammed and two other al-Qaida leaders, Ramzi Binalshibh and Abu Zubaydah, according to the Pentagon.

Washington's surprising announcement had followed previous refusals to admit the existence of secret CIA prisons. The detention program, which was revealed by the media last year, prompted an international outcry.

"The High Commissioner recalled that secret and incommunicado detention in themselves had infringed international law and could create an environment ripe for other abusive conduct," Diaz said.

Arbour, a former UN war crimes prosecutor and Canadian Supreme Court judge, has previously called for closing secret detention centers as well as Guantanamo Bay.

Although they can receive the International Committee of the Red Cross (ICRC) visits, many Guantanamo detainees have been held without trial for years, and Arbour also cited allegations of abuse there.

According to Arbour's spokesman, UN special investigators are due to report on Guantanamo at the next three-week session of the UN Human Rights Council which opens in Geneva on September 18.

The Geneva-based ICRC also plans to visit the 14 terrorism suspects at Guantanamo Bay next week.

Source: Xinhua