A senior Russian military official says Moscow is still reviewing the possible delivery of the S-300 air defense systems to Iran.

"The issue of S-300 deliveries [to Iran] is still under discussion. There are some technical and other problems," said Konstantin Biryulin, Russia's Deputy Director of the Federal Service for Military-Technical Cooperation.

"I do not understand why there is so much media frenzy over the deliveries of S-300 to this region ... Russia has the right to decide on its own whether to deliver these systems to any country which is not under UN Security Council's sanctions," RIA Novosti quoted Biryulin as saying on Thursday.

Iran's Defense Minister Ahmad Vahidi had earlier said that Moscow has a "contractual obligation" to deliver the advanced S-300 air defense systems to Tehran.

"We have made a deal with the Kremlin to buy S-300 defense missiles," said Vahidi in a Wednesday interview with ILNA news agency.

"We don't think Russian officials would want to be seen in the world as the ones who breach the contract," he added.

Russia signed a contract with Iran in December 2005 under which it would supply the country with the S-300 air defense systems.

MGH/SS/RE