UNITED NATIONS - A U.N. human rights expert is calling on the United States to prosecute or release suspects detained as “unlawful enemy combatants” and to move quickly to close the Guantanamo Bay prison camp.

Martin Scheinin, the U.N.’s independent investigator on human rights in the fight against terrorism, said in a report released Monday that he’s concerned about U.S. detention practices, military courts and interrogation techniques.

He urged the U.S. government to end the CIA practice of extraordinary rendition, in which terrorism suspects are taken to foreign countries for interrogation.

Scheinin said he was also concerned about what he termed “enhanced interrogation techniques reportedly used by the CIA,” saying that under international law “there are no circumstances in which cruel, inhuman or degrading treatment may be justified.”

The U.S. military defended the current process. “Unlawful enemy combatants held at Guantanamo are afforded more due process than any other captured enemy fighters in the history of warfare,” U.S. Navy Cmdr. Jeffrey Gordon, a Defense Department spokesman on Guantanamo, told The Associated Press. “We will enforce the law as spelled out in the Military Commissions Act of 2006.”

Gordon, who said appropriate officials will review the report, added that the U.S. will move cautiously on Guantanamo.

“While we have stated our desires to close Guantanamo, it would be irresponsible to release these dangerous men into the general population,” he said.

Scheinin, a law professor from Finland appointed by the Geneva-based U.N. Human Rights Council, issued a preliminary report after visiting the United States in May. His final report was issued on Monday, coinciding with the report to the U.N. General Assembly’s human rights committee.

Scheinin expressed regret to the committee that he couldn’t interview detainees at Guantanamo in private.

Scheinin also welcomed his recent invitation by the U.S. government to Guantanamo to observe proceedings before military commissions.

In the report, Scheinin called for the abolition of the military commissions which were established in 2001 by President and declared unlawful by the U.S. Supreme Court in 2006 because they were not authorized by Congress. Congress responded by passing the Military Commissions Act of 2006.

Scheinin said the offenses in the 2006 law - including terrorism, wrongfully aiding the enemy, spying and conspiracy - “go beyond offenses under the laws of war.” He argued that the offense did not apply at the time of the alleged acts by detainees, and maintained that the commissions are applying criminal law retroactively in violation of international law.

Due to various concerns, Scheinin recommended the abolition of the commissions. “Wherever possible, ordinary civilian courts should be used to try terrorist suspects,” he said.

Scheinin also recommended that the U.S. government abandon “the categorization of persons as `unlawful enemy combatants,’” calling it a “a term of convenience without legal effect.”

The report called on the “United States to release or to put on trial those persons detained under that categorization.”

While acknowledging the need to bring those accused of war crimes to justice, Scheinin emphasized that “the chance of ensuring a fair trial diminishes over time.” He added that “the detention of persons for a period of several years without charge fundamentally undermines the right of fair trial.”

Scheinin called on the U.S. to lift restrictions that prohibit Guantanamo Bay detainees to seek “full judicial review of their combatant status.” The U.S. prohibition violates the International Covenant’s prohibitions on arbitrary detention, the right to a judicial review which could grant freedom, and the right to a fair trial within a reasonable time, he said.

He urged “determined action” to move toward Bush’s goal of closing Guantanamo.

Scheinin said he has been advised that up to 80 detainees will be tried by military commissions, and that the U.S. wants to return the rest to their countries of origin or to a third country. He said the U.S. and the U.N. should work together to resettle detainees in accord with international law.

© 2007 The Associated Press.