NEW YORK, Sept 24, (Agencies): US National Security Adviser John Bolton said on Monday that Russian plans to supply Syria with a S-300 missile system would be a “significant escalation” by Moscow and hopes it will reconsider.Russia announced on Monday it will supply the surfaceto- air missile system to Syria in two weeks against strong Israeli objections, a week after Moscow blamed Israel for indirectly causing the downing of a Russian military plane in Syria.The Russian military’s reconnaissance Il-20 was shot down by the Syrian government missile defense systems responding to an Israeli airstrike. All 15 people on board were killed. Russia laid the blame on Israel, saying Israeli fighter jets had pushed the plane into Syria’s line of fire. Syria’s skies, where regional and international powers back different parties in the conflict, are increasingly crowded.Shortly before the downing, Israeli strikes had hit targets inside Syria, reportedly preventing an arms shipment to the Iranian-backed militant Hezbollah group. Russia launched its campaign in Syria to support President Bashar Assad in 2015, and though the involvement turned the tide of war in favor of Syrian government forces, Moscow has tried to play a careful balancing act, maintaining good ties both with Iran and Israel.For its part, Israel is wary of Iran’s growing influence in Syria. President Vladimir Putin initially struck a reconciliatory note, blaming the downing on a “chain of tragic, fatal circumstances.” But the Russian military came out on Sunday, renewing the accusations against Israel. Russian officials said Syria’s outdated S-200 systems weren’t sophisticated enough to identify the Russian plane as a friendly one. Monday’s statement from Russian Defense Minister Sergei Shoigu said Russia will send the S-300 missile defense systems to Damascus within the next two weeks. Earlier in the war, Russia suspended a supply of S-300s, which Israel feared Syria could use against it.