Iran's armed forces have completed the first stage of a large-scale air defense exercise to protect the country's nuclear facilities, the ISNA news agency quoted the air force and air defense staff as saying.

The five-day exercise, dubbed Asemane Velayat 2, started Sunday and comprises three stages. It covers a vast area in the northwest, west, south and southwest of the country.

The Islamic Revolution Guards Corps and Iran's regular armed forces are involved in the exercise.

"In line with the exercise plan, the second stage starts immediately upon the completion of the first stage," the staff said.

Iran frequently holds military drills and shows off modern weaponry in an effort to demonstrate its readiness to thwart any attack against its nuclear facilities.

The West led by the United States accuses Iran of pursuing a secret nuclear weapons program but the Islamic Republic says it needs nuclear power solely for civilian purposes.

The U.S. and Israel have not ruled out military action against Iran to stop the Islamic Republic from obtaining nuclear weapons.

A senior official of the Iranian Revolutionary Guards Corps said Saturday that Iran would retaliate against Israel, if attacked.

"If the enemy attacks Iran, our missiles will strike Tel Aviv," Mojhtaba Zolnoor, supreme leader representative in Revolutionary Guards, was quoted by the ILNA news agency as saying.

MOSCOW, November 23 (RIA Novosti)