”US army helicopters have been spotted flying close to the borders of Iraq with the Islamic republic," an armed forces headquarters statement said.
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.
The hardliners not being pleased with the results is one interpretation. Another is that the Iranians are concerned about a potential military strike against Iran during the last days of the Bush Administration, something that has been discussed at length in the international press.