MOSCOW, Dec. 27 (Xinhua) -- Russia is assisting Iran to strengthen the country's air defense capability, Russia's deputy foreign minister told reporters on Thursday.

    "I know we are assisting in work to reinforce Iran's air defense systems," Alexander Losyukov was quoted by the RIA Novosti news agency as saying.

    "I have no concrete information on the issue and can make no comment whatsoever on the type of (military) hardware," he said.

    Iranian Defense Minister Mostafa Mohammad Najjar said Tehran has signed a contract with Russia on Tuesday for the delivery of the advanced S-300 air defense missile systems, Iran's Fars news agency said on Wednesday.

    The defense minister provided no details of the deal or any timeline for the delivery of the system.

    The signing of the deal follows last week's meeting on military-technical cooperation between the two nations in Tehran, where both sides reviewed existing agreements and discussed further steps to enhance military cooperation.

    Air defense and radar systems are the priority directions in Russia-Iran military cooperation, Mikhail Dmitriyev, director of Russia's federal service for military-technological cooperation, said last week.

    Dmitriyev said its military cooperation with Iran strengthens stability in the region.

    The advanced version of the S-300 missile system, called S-300PMU1 (SA-20 Gargoyle), has a range of over 150 kilometers and can intercept ballistic missiles and aircraft at low and high altitudes, making this system an effective tool for warding off possible air strikes on Iran.

    Moscow earlier supplied Iran with 29 Tor-M1 air defense missile systems under a 700-million-dollar contract signed in late 2005. Russia has also trained Iranian Tor-M1 specialists, including radar operators and crew commanders.