Iran on Wednesday completed the first day of the third stage of an air-defense exercise, which saw the test firing of modern missile systems, the ISNA news agency said.

Iran launched on Sunday a five-day drill, Sky of Velayat 2, designed to strengthen its aerial defense against potential attacks on its nuclear facilities.

The exercise reportedly covers 600,000 square kilometers, spanning the central, western and southern parts of the country.

"Advances in the defense capabilities of the air force and the Islamic Revolution Guards Corps... enabled the country to counter attacks by state-of-the-art missiles," Brigadier General Ali Moqiseh was quoted as saying.

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 suspects 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 taking military action against Iran to stop it from obtaining nuclear weapons.

MOSCOW, November 25 (RIA Novosti)