Amos Gilad, head of the ministry's Security-Diplomatic Bureau, landed in Moscow on Wednesday to convey Israel's opposition to the deal. While in Russia, Gilad will also address the possible sale of weapons to Syria and the flow of arms through Syria to Hizbullah terrorists in Lebanon.
Jerusalem contends that equipping Iran, Syria and Hizbullah with Russian defense systems would disturb the balance of power in the Middle East. Israel's fear is based on the talks Moscow has been conducting with Tehran and Damascus on these matters.
Reuters reported Wednesday that Russia is currently fulfilling a contract to deliver S-300 anti-aircraft missiles to Iran. In October Russia's Foreign Ministry denied media speculation that Moscow would sell the S-300 system, which could help the Islamic republic fend off air strikes by arch foes Israel and the United States on its nuclear sites.
A Foreign Ministry spokesman at the time said that Moscow had no intention of selling weapons to "troubled regions".
But quoting unnamed sources, the RIA news agency said that Russia and Iran were holding talks on sales of medium-range air defense systems.
"Moscow has earlier met its obligations on supplying Tor-M1 systems to Iran and is currently implementing a contract to deliver S-300 systems," RIA reported.
The Tor-M1 is a short-range surface-to-air missile system.
Prime Minister Ehud Olmert returned encouraged from his visit to the Kremlin in October, but as it turns our President Dmitry Medvedev did not promise him that Russia would not sell the defense systems to Iran. The chances that Syria will obtain these systems are slim.
Reuters contributed to the report