John Bolton
John BoltonReuters

The US National Security Advisor said Tehran should be held responsible for last week’s downing of a Russian military plane over Syria, and warned Monday that Russian plans to transfer advanced anti-aircraft missile systems to Syria represented a major escalation in an already tense region.

Speaking with reporters on Monday, President Donald Trump’s National Security Advisor, John Bolton, rejected statements by the Russian Defense Ministry holding Israel responsible for the loss of an Ilyushin IL-20 reconnaissance aircraft over Syria last week.

“There shouldn’t be any misunderstanding here,” said Bolton Monday. “The party responsible for the attacks in Syria and Lebanon and really the party responsible for the shooting down of the Russian plane is Iran.”

Last Tuesday, a Russian IL-20 was shot down over Syria, apparently by a Russian-made S-200 anti-aircraft missile fired by the Syrian air defense network following an Israeli airstrike on a Syrian military research facility.

Russian officials blamed Israel for the downing of the IL-20 and the loss of the 15-member crew, claiming that the Israeli jets had intentionally used the much larger Russian plane to mask their radar signatures.

The IDF denied Russia’s accusations, claiming the Israel Air Force jets were already out of the combat zone and in Israeli airspace when the IL-20 was downed, and that the IL-20 had been far from the area of the airstrikes during the Israeli operation.

An IDF delegation was dispatched to Moscow last week to share information collected by Israel as part of its investigation into the incident.

On Monday, however, Russian President Vladimir Putin told Prime Minister Binyamin Netanyahu that he did not accept the IDF’s claims regarding the incident.

"The information provided by the Israeli military...runs counter to conclusions of the Russian defense ministry," the Kremlin said in a statement following Putin’s call with Netanyahu.

Putin also discussed with Netanyahu Russian plans to transfer S-300 missile systems to Syria following the downing of the IL-20.

Netanyahu warned that the the transfer of the missiles to “irresponsible hands” was “dangerous”.

“The Prime Minister said that the transfer of advanced weapons systems to irresponsible hands would make the region more dangerous, and that Israel would continue to defend its interests and security,” the Prime Minister’s Office said Monday evening.

Bolton also criticized the move, saying that the transfer constituted a “significant escalation”.

“We think introducing the S-300s to the Syrian government would be a significant escalation by the Russians,” Bolton said, “and something that we hope, if these press reports are accurate, they would reconsider.”

The National Security Advisor also said that the US would retain its military assets in Syria until Iran withdraws its forces from Syrian territory.

“We’re not going to leave as long as Iranian troops are outside Iranian borders, and that includes Iranian proxies and militias.”

The US currently has some 2,500 troops deployed in Syria.