The Pentagon dismissed a United Nations report on Monday that criticized the United States for the conditions and treatment of detainees at Guantanamo Bay.
The U.N. draft report, which has not yet been officially released, called for the prison to be closed, citing torture acts and prolonged solitary confinement.
"These are the same individuals that we offered an opportunity to go down and see first hand the operations at Guantanamo, who declined the offer and so their report suffers from the first hand account that they could have had," said Bryan Whitman, a Pentagon spokesman.
The Pentagon had offered U.N. officials a visit to the facility, but Whitman acknowledged that the experts would not have had direct access to the detainees.
"The operations at Gitmo have been about as transparent as one could make them with respect to not only the international organizations, but members of Congress and the press," Whitman said.
The government's policy does not allow direct access, except to the International Committee of the Red Cross.
"Just because they decided not to take up the U.S. government on the offer to go to Guantanamo Bay does not automatically give the right to publish a report that is merely hearsay and not based on fact," said State Department spokesman Sean McCormack.
"The apparent attempts by the U.S. administration to reinterpret certain interrogation techniques as not reaching the threshold of torture in the framework of the struggle against terrorism are of utmost concern," the draft report said.
The draft report, which follows repeated claims by prisoners at Guantanamo Bay that they have been mistreated or denied their rights, was delivered to the United States on Jan. 16. It was first disclosed Sunday by the Los Angeles Times.
"They are taking assertions by individuals who have left Guantanamo, as well as their lawyers, as fact," McCormack said of the investigators. "And, as we have seen over the past year, there have been a number of baseless claims about what went on at Guantanamo."
American officials said the most significant flaw of the report was that it judged U.S. treatment of detainees according to peacetime human rights laws. The United States contends it is in a state of conflict and should be judged according to the laws of war.
"Once you fail to even acknowledge that as the legal basis for what we're doing, much of the legal analysis that follows just doesn't hold," a State Department official said.
The official spoke on condition of anonymity because the United States has not formulated an official public response to the draft.
The report will be presented to the next session of the human rights commission.
"In the case of the Guantanamo Bay detainees the U.S. executive operates as judge, as prosecutor, and as defense counsel," the report said. "This constitutes serious violations of various guarantees of the right to a fair trial before an independent trial."
Manfred Nowak, the U.N. special investigator on torture and one of the five experts, said the report was a draft and had not incorporated U.S. comments. It was expected to be made public later in the week.
U.S. officials faulted the experts for rejecting an invitation to visit Guantanamo Bay, saying it fundamentally undermined the accuracy of their findings.
"The U.N. rapporteurs were invited to visit Guantanamo Bay and they chose not to," said Richard Grenell, spokesman for the U.S. mission to the United Nations in New York. "Had they visited, they would have found that there is no torture going on."
The five experts accepted the offer by the United States to visit the facility in December but didn't go when they were informed they couldn't interview detainees.
"We invited these individuals to visit Guantanamo Bay. They refused the invitation," McCormack said.
FOX News' Bret Baier and Nick Simeone and The Associated Press contributed to this report.