The S-400, the S-300 and the Pantsir air defense systems protect the Russian air group at the Hmeymim airfield from the air, the Russian ministry said.
"The Russian air defense system in the Syrian Arab Republic is aimed at protecting certain facilities and objects. The S-400, S-300 surface-to-air missile systems and the Pantsir-S1… complex provide solid protection to the Russian bases from the air," ministry's spokesman Ifor Konashenkov said.
He emphasized that the S-400 and Pantsir systems provide guaranteed protection to the Russian air group at the Hmeymim airfield, while another air defense group deployed in Syria consists of the S-300 and Pantsir systems is protecting the Russian Navy logistics center in Tartus.
"Combat calculations of the Russian air defense systems in the Syrian Arab Republic are on duty around the clock."
On Thursday night, the United States launched 59 Tomahawk cruise missiles at the Syrian military airfield in Ash Sha’irat, located about 40 kilometers (25 miles) from the city of Homs. US President Donald Trump said the attack was a response to the alleged chemical weapon use in Syria's Idlib on Tuesday, which Washington blames on the Syrian government.
The S-400 system was deployed at the Hmeymim following the Turkish Air Force's November 2015 downing of a Russian Su-24 bomber on the Syrian-Turkish border.
In October 2016, the Russian Defense Ministry said that a S-300 system was sent to Syria to ensure the safety of the Russian naval base in Tartus. According to media reports, the system deployed in Syria is S-300V4 — NATO designation SA-23 Gladiator — that is capable of striking tactical and strategic aircraft, medium-range ballistic missiles, tactical missiles as well as cruise missiles.