Iranian Foreign Ministry spokesman Mohammad Ali Hosseini's announcement Monday is the first official confirmation that the talks will be suspended.
Iran's semi-official Fars news agency quoted an unnamed senior Iranian negotiator Saturday as saying new talks were not possible with continued U.S. attacks against the Iraqi people.
U.S. and Iraqi forces have been battling supporters of radical Shia cleric Muqtada al-Sadr. Washington has accused Iran of supporting Shia militias in Iraq, a charge denied by Tehran.