Russia is unlikely to go ahead at this time with the sale of state-of-the-art S-300 anti-aircraft missiles to Iran, in an effort to improve Moscow's ties with the new administration in Washington, according to reports in the Russian media on Tuesday. The reports came amid a visit to Moscow by Iranian Defense Minister Mostafa Muhammad Najjar, who met his Russian counterpart Anatoly Serdyukov on Tuesday in an apparent bid to persuade the Kremlin to sell Teheran the anti-missile systems that would significantly complicate any Israeli or US strikes on Iranian nuclear installations. The proposed sale of the arms to Iran was discussed on Sunday and Monday in Jerusalem during what Israeli officials described as "very good" talks with visiting Russian Foreign Minister Sergey Lavrov. Lavrov met with President Shimon Peres, Prime Minister Ehud Olmert, Foreign Minister Tzipi Livni and opposition leader Binyamin Netanyahu. Israel "heard from him very clearly that Russia would not sell weapons to any countries in the area that would tip the strategic balance in the region," one source said. The S-300 is considered to be just such a weapon. The source said that Lavrov, in a reference to Israeli arms sales to Georgia, said Moscow expected Israel "to show the same responsibility." The question of Israeli arms sales to Georgia arose last year during the Russian-Georgia crisis over South Ossetia. Israel maintained that it was only selling defensive, not offensive arms, to Georgia. Russia's Kommersant newspaper reported Tuesday that Russia and Iran had already signed an $800 million deal for five of the S-300 systems, but Moscow had not yet decided whether to ratify the sale. Pravda carried a story on its Web site Tuesday saying that Russia - at least for now - was not approving the sale since that might hurt Moscow's dialogue with the new Obama administration. Lavrov is scheduled to meet US Secretary of State Hillary Clinton next month, and Russian President Dmitry Medvedev is to meet US President Barack Obama in April to discuss nuclear disarmament issues and the deployment of US missiles in Eastern Europe. Selling S-300s to Iran now, Pravda reported, would mar the atmosphere of those talks. The S-300 is one of the most advanced multi-target anti-aircraft missile systems in the world, and has a reported ability to track up to 100 targets simultaneously while engaging up to 12. The S-300 system was first deployed by the USSR in 1979 and was designed to defend large industrial and administrative facilities and military bases, and to control airspace against enemy aircraft. It has a range of about 200 km. and can hit targets at altitudes of 27,000 meters. Iran already has Russian-made TOR-M1 surface-to-air missiles, but they have a shorter range than the S-300.