The independent National Security Archive published documents Monday linking the CIA to a 1953 coup that deposed Iranian Prime Minister Mohammed Mossadegh. The documents from the CIA's internal records from the 1970s on Iran said the military coup ousting the prime minister was carried out under the direction of the intelligence agency.
Iranian Foreign Ministry spokesman Abbas Araqchi said Tuesday the Iranian government was not surprised by the information.
"[The release] neither adds anything new to what we already knew, nor does it lessen the American crimes," he was quoted by Iran's state-funded broadcaster Press TV as saying.
National Security Archive said U.S. and British involvement in the 1953 coup has long been public knowledge, though it said Monday the revelation is believed to be the first time the CIA admitted to playing a role in the coup.
The revelation comes as Western leaders work to assess how Iranian President Hassan Rouhani would govern. Iran's former chief nuclear negotiator ran as a moderate during the campaign season, pledging to reach out to the international community during his first term in office.
Rouhani said Monday his administration would be guided by policies of "political moderation, economic prudence and social optimism."