Russian President Vladimir Putin informed Syrian President Bashar al-Assad, through a telephone call on Sept. 24, about his decision to supply Damascus with a modern S-300 missile system. Russian Defense Minister Sergei Shoigu additionally announced that Russia will also deliver an automated control system for its air defense.

The military arsenals are expected to reach Syria in two weeks.

The announcement was made a week after Syrian forces by mistake shot down a Russian aircraft while they conduct an Israeli air strike. Moscow was determined that an Israeli fighter jet had deliberately used the Russian aircraft as a shield against air attacks from Syria.

Reacting on Russia's decision to supply Syria with S-300 missile system, U.S. National Security Adviser John Bolton said Moscow's missile sale to Damascus would be a "significant escalation." He called on for his Russian counterparts to reconsider their pronouncement.

With the recent development, Bolton said U.S. troops would continue to participate in the Syrian war as long as Iran forces, their proxies, and militias are participating.

The United States was compelled to deploy troops to fight in Damascus after the Syrian government was found to be guilty of using chemical weapons.

Russia, on the other hand, is participating in the Syrian War in support of al-Assad's regime

Reports were not immediately clear on whether Russia is donating, selling or lending the missile system to Syria.

In August, a report from the United Nations' Economic and Social Commission for Western Asia unit stated that the seven years of war in Syria had already cost economic damages of as much as $400 billion. The report was presented during a two-day meeting attended by more than 50 Syrian and international war experts.

ESCWA said that the war in Syria has destroyed more than $388 billion in physical capital and sectoral distribution alone. The estimates presented during the meeting did not include monetary amounts converted from loss of human lives, loss of human talents, and loss of skills in the labor sector. The last two factors were important drivers of the Syrian economy. 

During their telephone call, Putin and al-Assad highlighted their joint goal of achieving a long-term peace in Syria by restoring its sovereignty and territorial integrity.

Prime Minister of the State of Israel Benjamin Netanyahu has called Putin in the same day. He expressed his condolences on the deaths of Russian forces aboard the downed aircraft in Syria.

Netanyahu took the opportunity to have Putin reconsider its decision on supplying Syria with the missile system. He explained that the missile could endanger more lives if it was given to irresponsible parties. The Israeli leader also presented the information from the Israeli military, asserting that its aircraft was operating within its border and that negligence should be taken against the Syrian defense crew.

Putin, however, insisted that the actions of the Israeli Air Force were the main cause of the tragedy.