Iran has launched a three-day series of Air Force and missile defense exercises throughout the country, the Air Force commander said on Monday. "The drills are being conducted in more than a half of Iran's provinces.

Their main goal is to rehearse tactical operations with modern weapons and generally to upgrade the operational effectiveness of the country's armed forces," Brigadier General Ahmad Mighani said.

He said all air-defense units of Iran's Ground Forces would be involved, including during launches of advanced missiles and other precision guided weapons.

Iran has conducted several high-profile war games this year, while promising a powerful retaliation in the event of any act of aggression against the country. The U.S. and Israel have consistently refused to rule out the possibility of military action against Iran over its refusal to halt its nuclear program.

Iran recently took delivery of 29 Russian-made Tor-M1 air defense missile systems under a $700-million contract signed in late 2005. Russia has also trained Iranian Tor-M1 specialists, including radar operators and crew commanders.

In July Iran successfully launched an upgraded Shahab-3 ballistic missile with a range of 2,000 km (1,240 miles), and several missiles with a range of 350 kilometers (217 miles) as part of the Great Prophet III military exercise in the Persian Gulf and the Strait of Hormuz, drawing a new wave of international criticism.

Iran is currently under three sets of relatively mild UN Security Council sanctions for defying demands to halt uranium enrichment, which it says it needs purely for electricity generation despite Western accusations that the program is geared toward weapon production.