The acknowledgement was made in a report submitted to the UN Committee against Torture, said a member of the ten-person panel, speaking on on condition of anonymity.
"They are no longer trying to duck this and have respected their obligation to inform the UN," the Committee member said.
"They they will have to explain themselves (to the Committee). Nothing should be kept in the dark," he said.
UN sources said this is the first time the world body has received such a frank statement on torture from US authorities.