Moscow is trying to persuade Tehran to withdraw its lawsuit against Russia’s state-run arms export company Rosoboronexport over a cancelled deal to supply S-300 air defense systems to Iran, Russian Technologies (Rostech) CEO Sergei Chemezov said. Iran’s Defense Ministry and The Aerospace Industries Organization have launched a $4 bln lawsuit against Rosoboronexport in an international arbitration court in Geneva in April 2011. Moscow was to supply five S-300PMU-1 battalions to Tehran. However, on September 22, 2010, Russian President Dmitry Medvedev signed a decree cancelling the contract in line with UN Security Council Resolution 1929, which bans supply to Iran of conventional weapons including missiles and missile systems, tanks, attack helicopters, warplanes and ships. Tehran has insisted that the S-300 surface-to-air missile systems do not fall under the UN sanctions as they are considered defensive weapons. Chemezov criticized on Thursday the United States for the lack of support in the case. He said Washington applied heavy pressure on Moscow to stop the deal but later changed its rhetoric saying the UN resolution did not mention specifically the S-300, known in the West as SA-10 Grumble, and Russia acted on its own. “The Americans now agree that it is a defensive system and Russia alone should be responsible for the breach of the contract,” Chemezov said.