The question of the transfer of S-300 ground-based air defence systems to Syrian army had already been resolved, that was reported by the newspaper Kommersant.

According to Russian media, this matter was under “mainly in at the political level”. S-300 air defence systems are planned to hand over to Damascus as part of a military donation since the purchase of “the Syrians does not have money”, and the loan is not included in Russia’s plans.

Components of the S-300 (radar stations, transport-loading machines, self-propelled command posts, launchers, etc.) will soon be delivered to Syria either by air transport aircraft or by Russian Navy ships, said in a Russian newspaper.

More: Ukraine to modernise S-300V1 air defence system

After the U.S.-led missile strikes on Syrian regime chemical weapons sites, the Russian government responded with a number of vague and unspecified threats, including the suggestion it could reconsider selling S-300 surface-to-air missile systems to Syria’s dictator Bashar Al Assad.

The US attack on Syria has absolved Russia of its “moral obligation” to hold back on supplying an advanced air defense system to Syria, the Russian foreign minister said.

More: China conducts massive exercise with Russian-made S-300 surface-to-air missile systems

The possible delivery of the Russian air defense systems is expected to cause further tension over Syria as it would certainly alarm Israel, which enjoyed freedom of movement in Syrian air space for years. Since the start of the Syrian civil war in 2011, Israel has carried out at least 150 bombing raids in Syria, according to the former Israeli ambassador to Moscow, Zvi Magen.