The report was denounced by the White House, reports CBS News correspondent David Martin and 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 Wednesday in Geneva and, 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.
Annan said the report by a U.N.-appointed independent panel was not a U.N. report but one by individual experts. "So we should see it in that light," he said.
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 Guantanamo report was an easy target for the Bush Administration to criticize because this is a case where the message may be right but the messenger lacks credibility," says CBS News Foreign Affairs Analyst Pamela Falk, who has been to the Guantanamo base twice. "The report was produced by the same U.N. Human Rights Commission that has been discredited by the Secretary General himself because some of its members have been the worst human rights violators, including Syria, Sudan, Cuba and Zimbabwe."
Manfred Nowak, the U.N. investigator for torture who was one of the panel's experts, told The Associated Press in Geneva that the detainees at Guantanamo "should be released or brought before an independent court."
"That should not be done in Guantanamo Bay, but before ordinary U.S. courts, or courts in their countries of origin or perhaps an international tribunal," he said.
The United States should allow "a full and independent investigation" at Guantanamo and also give the United Nations access to other detention centers, including secret ones, in Iraq, Afghanistan and elsewhere, Nowak said by telephone from his office in Vienna, Austria.
"We want to have all information about secret places of detention because whenever there is a secret place of detention, there is also a higher risk that people are subjected to torture," he said.