The move comes amid growing tension with the West. On Monday, the US halted talks with Russia on trying to co-ordinate air strikes against jihadists.
A ceasefire brokered by Washington and Moscow collapsed last month.
Background: How Russia's S-400 Air Defense System makes the super expensive F-35 stealth fighter obsolete ~ link ~
An S-300 missile fired from, say, Damascus will blow away an aircraft over central Tel Aviv in about 107 seconds, giving the Israelis just enough time to say their prayers. It is precisely because the S-series missile systems can so dramatically upset the military balance that Israel has pressured Russia against introducing it into the Middle East tinderbox. Israel has also warned it would go after Syrian S-300 batteries with everything it’s got.