Iran has turned down a request by the US for a rare bilateral meeting on the sidelines of nuclear talks between the Islamic republic and six world powers in Istanbul, the official IRNA news agency said.
There was no comment from US diplomats, whose country has not had direct ties with Tehran for more than three decades.
IRNA's report followed contradictory accounts from two other Iranian news agencies on prospects for a meeting between Iranian chief nuclear negotiator Saeed Jalili and the head of the US delegation, Under Secretary of State for Political Affairs Wendy Sherman.
The United States and Iran broke off diplomatic ties after the 1979 Islamic revolution which toppled the US-backed shah and both sides view each other with deep mistrust.
"The Iranian delegation rejected the request of Wendy Sherman, the representative of the American delegation, for a bilateral meeting," IRNA said.
The semi-official Fars news agency had earlier quoted an "informed source" as denying a report by a third agency, ISNA, that Jalili accepted a request for a meeting with a US envoy.
Non-Iranian diplomats attending the talks in Istanbul had questioned the ISNA report but still said Saturday's meeting between Iran and the six powers - the United States, Russia, France, China, Germany and Britain - had started well.
IRNA said Iranian diplomats in Istanbul did hold bilateral meetings today with Russian delegates and with EU foreign affairs chief Catherine Ashton, the main representative of the negotiating group of international powers, as well with the Turkish hosts, who are not party to the negotiations.
The West accuses Iran of trying to develop a nuclear weapons capability. Iran says its programme is peaceful.
Tehran agreed to resume talks with the six - the five permanent members of the UN Security Council plus Germany – after more than a year of escalating rhetoric and tensions.
Reuters