Last week, the U.S. ambassador to Iraq, Zalmay Khalilzad, said he had been authorized by the State Department to meet Iranian officials for talks on Iraq.
Iranian officials on 29 November ruled out such talks.
And speaking in Tehran today, Foreign Ministry spokesman Hamid Reza Assefi again poured cold water on the proposal.
"Negotiations with America were not on our agenda," Assefi said. "The issue of security in Iraq is an internal matter related to the Iraqis. The Iraqi people are mature and wise and they should determine their own future. So there is no need for negotiations with America."
Khalilzad today said he would urge Iranian officials to play a more constructive role in Iraq.
The United States and the Iraqi government have accused Syria, and also Iran, of allowing foreign fighters to cross into the country. Both countries deny the charges.