In December 2007, Russia's Federal Service for Military-Technical Cooperation said that the issue of the delivery of S-300 air defense missile systems to Iran, raised by the media, was not a subject of current negotiations and had not been discussed with the Iranians.
"The statement that many considered to be a denial of the negotiations on S-300 was simply a statement by a Russian official who referred to the latest round of military cooperation talks in Tehran [in December 2007]," Mehdi Safari said in an interview with the Iranian Students' News Agency (ISNA).
"However, the sides [Iran and Russia] are continuing work to study the possibility of delivering these [S-300] systems to Iran," Safari said.
The issue was first raised in December last year when Iranian Defense Minister Mostafa Mohammad Najjar said that Iran and Russia had agreed to deliver an unspecified number of advanced S-300 air defense complexes to the Islamic Republic under a previously signed contract.
The advanced version of the S-300 missile system, called S-300PMU1 (SA-20 Gargoyle), has a range of over 150 kilometers (about 100 miles) 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.
U.S. authorities have repeatedly called on Russia to stop arms deliveries to countries whose political regimes Washington disapproves of, including Iran.
However, Russian President Vladimir Putin said in October last year that Russia would not take into consideration attempts to impose arms deal restrictions "based on unilateral and politicized assessments". He said deliveries of Russian weapons were aimed exclusively at increasing the defense capability of the countries receiving them, and at maintaining their stability.
Moscow supplied Iran with 29 Tor-M1 air defense missile systems in late January under a $700-million contract signed in late 2005. Russia has also trained Iranian Tor-M1 specialists, including radar operators and crew commanders.