BBC - Iran has accused US helicopters of flying close to its airspace and warned it would "take down" any overflying aircraft not responding to warnings.
"US army helicopters have been spotted flying close to the borders of Iraq with the Islamic republic," an armed forces headquarters statement said.
Last month, US helicopters raided Syria killing eight people, although the US has not commented on the raid.
"Iran's armed forces will respond to any violation," the statement said.
Washington's arch-foe Tehran has blamed the US for increasing the insecurity in the region and has called for its troops to pull out of Iraq.
Washington accuses Iran of supporting international terrorism and militants in Iraq, as well as illegitimately seeking to develop nuclear weapons.
An Iranian politician quoted by Reuters said the statement seems to have been timed with the election victory of Barack Obama, suggesting they are "not very happy".
This is because Iran's hardline leaders thrive on confrontation with the US, correspondents say, and Mr Obama has spoken about the possibility of opening direct political dialogue with Tehran.
"This is a clear message to the American president-elect because radicals are not very happy that Obama has been elected," the politician is quoted saying, speaking anonymously.
