Iranian officials on Wednesday welcomed Barack Obama's victory in U.S. presidential elections, calling it a sign of failure of President George Bush's policies and Americans' demand for essential changes.

"Obama's election as the U.S. president shows the American people's demand for essential changes in the country's domestic and foreign policies," Iranian Foreign Minister Manouchehr Mottaki was quoted as saying by the official news agency IRNA, while urging the new administration "to distance itself from the wrong approaches of current politicians."

As the first reaction by an Iranian official earlier on Wednesday, Gholam-Ali Hadad-Adel - senior advisor to Iran's supreme leader - said the victory of the slogan of "change" is the admission of the American people to the failure of Bush's policies.

"The next U.S. president should abandon the course taken by President Bush and the American people have to change their policies in order to get rid of the quagmire that he created for them," former parliament speaker Hadad-Adel was quoted as saying by Iranian media.

The reactions to the U.S. elections came after a harshly worded statement issued earlier this morning by Iran's military, warning American forces in Iraq that it would strongly respond to any violation of Iranian airspace.

"American military helicopters were recently flying in short distances from Iraq's joint borders with Iran and while the borders are not straight there would be the possibility of violating Iran's airspace," Iran's army headquarters said in a statement carried by IRNA.

"So Iranian armed forces would strongly respond in case of any violations," said the statement.

Washington, which has no diplomatic ties with Tehran, accuses Iran of fuelling an insurgency in Iraq by equipping and training militants and also has accused Tehran of seeking nuclear weapons.

Tehran denies the charges saying instability in Iraq is due to the presence of the American military and says that its nuclear programme is peaceful and aimed at generating electricity.

Observers believe that although Iranian leaders prefer Obama as the next U.S. president they are aware that there would be no major change in Washington's policies towards the Islamic Republic and the army's statement was a clear message to the new U.S. president about Iran's vigilance.

"The Islamic republic (of Iran) needs to keep its enmity with America, so you will witness the same stance towards the U.S. as before, but probably with a softer rhetoric if they see the same rhetoric from the new American administration," one political analyst told Deutsche Presse-Agentur under the condition of anonymity.

"This could be the best opportunity for Tehran to ease the tensions with Washington but through a moderate (Iranian) administration, not the current radical one headed by President (Mahmoud) Ahmadinejad," said the analyst.