Iran ? Russia is preparing to equip Iran with a powerful new air defense system that would dramatically increase its ability to repel an attack, Iran’s defense minister said Wednesday.

The S-300 anti-aircraft missile defense system is capable of shooting down aircraft, cruise missiles and ballistic missile warheads at ranges of over 90 miles and at altitudes of about 90,000 feet. Russian military officials boast that its capabilities outstrip the U.S. Patriot missile system.

The S-300 is an improvement over the Tor-M1 air defense missile system. Russia delivered 29 Tor-M1s to Iran this year under a $700 million contract signed in December 2005.

Iranian Defense Minister Mostafa Mohammad Najjar didn’t say when or how many of the S-300 anti-aircraft missile defense systems would be shipped to Iran, and Russian officials declined to comment.