On Sunday, the Russian Security Council stressed that there is no reason to not go ahead and deliver the S-300 air defense system to Iran.

Several years ago, Russia and Iran had reached a deal, under which the S-300 systems would be purchased by the latter, but there had been constant delays on the part of Russia over the delivery of the anti-aircraft missiles.

"There is signed contract that we must fulfill, but supplies have not started yet. This deal is not restricted by any international sanctions, because it only involves the delivery of purely defensive weapons. On the other hand, all of our actions must contribute to global and regional stability, respecting international law and international commitments, including those under the Non- Proliferation Treaty", said Vladimir Nazarov, Deputy Secretary of Russia's Security Council.

Some sources have suggested that the Russian-Iranian contract has managed to envision the sale of S-300 systems worth about $800 Million.