Russia has announced it is canceling its delivery of the S-300 missile defense system to Iran. The news came as a result of the increased sanctions imposed June 9 by the United Nations Security Council, according to Russian Deputy Minister of Foreign Affairs, Andrei Denisov.

Had it been delivered, military intelligence officials said the S-300 PMU1 system would have made Iran's nuclear plants “invincible” against any aerial attack. Pundits have speculated that Israel might attempt to derail Iran's nuclear development program with such an attack on at least one, if not several of its nuclear sites.

“Moscow believes that the sanctions resolution clearly forbids the sale of the S-300 system to Iran,” Denisov said, according to the Ria Novosti news service. The highly advanced truck-mounted SA-20 anti-aircraft missile system can detect and shoot down any incoming aircraft within a 120-kilometer (75-mile) range.

Russia had signed a contract with Iran in 2005 to provide the Islamic Republic with at least five of the systems. However, both Washington and Jerusalem have been exerting increasing pressure on Moscow to scrap the deal in the face of Iran's race towards probable development of a nuclear weapon. In February, Israeli Prime Minister Binyamin Netanyahu appealed to Russia to withhold the system, but was told the sale would go forward.