"According to information of our military experts, the reason (behind the downing) were premeditated actions by Israeli pilots which certainly cannot but harm our relations," Kremlin spokesman Dmitry Peskov told journalists.

Peskov's remarks followed an announcement by Russian Defence Minister Sergei Shoigu that Moscow will be sending an advanced S-300 air defence system to the Syrian military as well as jamming communications of any military planes that attack Syria from over the Mediterranean.

On September 17, a Russian Il-20 plane was hit by a Syrian S-200 air defence missile when it was landing following strikes by Israeli F-16 planes of western Syria. Moscow blamed the friendly fire incident on Israeli pilots using the larger Russian plane as "cover."

Peskov said the new measures were decided on to boost the security of its troops in Syria.

"Russia in this case is acting in its interests only, these actions are not directed against third countries, but towards defending our own military," he said.