UNITED NATIONS — Secretary-General Kofi Annan on Thursday said the United States should close the prison at Guantanamo Bay for terror suspects as soon as possible, backing a key conclusion of a U.N.-appointed independent panel.

White House spokesman Scott McClellan rejected the call to shut the camp, saying the military treats all detainees humanely and "these are dangerous terrorists that we're talking about."

The panel's report, released Thursday in Geneva, said the United States must close the detention facility "without further delay" because it is effectively a torture camp where prisoners have no access to justice.

Annan told reporters he didn't necessarily agree with everything in the report, but he did support its opposition to people being held "in perpetuity" without being charged and prosecuted in a public court. This is "something that is common under every legal system," he said.

"I think sooner or later there will be a need to close the Guantanamo (camp), and I think it will be up to the government to decide, and hopefully to do it as soon as is possible," the secretary-general told reporters.

The 54-page report summarizing an investigation by five U.N. experts, accused the United States of practices that "amount to torture" and demanded detainees be allowed a fair trial or be freed. The panel, which had sought access to Guantanamo Bay since 2002, refused a U.S. offer for three experts to visit the camp in November after being told they could not interview detainees.

U.N. spokesman Stephane Dujarric said the report will be presented to the U.N. Commission of Human Rights, which appointed the panel, when it convenes on March 13 in Geneva.

The United States is holding about 490 men at the military detention center. They are accused of links to Afghanistan's ousted Taliban regime or to al-Qaida, but only a handful have been charged.

Although his statement did not address specific allegations, the Pentagon has acknowledged 10 cases of abuse or mistreatment at Guantanamo, including a female interrogator climbing onto a detainee's lap and a detainee whose knees were bruised from being forced to kneel repeatedly.

In Strasbourg, France, the European Parliament condemned the treatment of prisoners at Guantanamo and renewed its calls for the detention center to be closed.

Human rights activists also supported the investigators' findings.

Amnesty International said the report was only the "tip of the iceberg."

"The United States also operates detention facilities at Bagram Airbase in Afghanistan, Abu Ghraib and elsewhere in Iraq and has been implicated in the use of secret detention facilities in other countries," an Amnesty statement said.