The Russian air force in Syria will be protected by the most powerful and advanced air defense system in the world, when it deploys its S-400 missile system to the Hmeymim airbase there.

Syria will have a comprehensive air defence after Russia deploys its S-400 missile systems to the Hmeymim airbase there, a security analyst and US Navy veteran Mark Sleboda told Sputnik.

​"It is a significant upgrade on the S-300, which was a much earlier system. The S-400 came out at the end of the Soviet period, but there have been significant upgrades in recent years."

"It is widely regarded by experts as the most powerful and technologically advanced air defence system in the world," and its deployment in Syria sends a powerful statement, said Sleboda.

"This is a very powerful defensive statement from Russia … very soon there will be a quite effective Russian no-fly zone over almost the entirety of Syrian territory, certainly covering all west of Syria, and very far towards the eastern border."

The deployment of S-400 is in addition to the Pantsir-S1 air defence missile-gun system the Russian air force already had at its disposal at the Hmeymim airbase, while the Moskva guided missile cruiser was already in the area.

"There wasn't really a need for them (the more powerful S-400 system)," said Sleboda.

"ISIL, of course, doesn't have an air force. They were simply a standard military precaution for an air mission. But now with the threat of NATO planes taking down Russian jets out of the air, that suddenly becomes a very real necessity."

On Wednesday the Russian defence ministry announced that the S-400 defence missile system will be deployed to its air base in Syria.

It can destroy tactical ballistic missiles at a range of up to 60 km, and air targets including cruise missiles and aircraft flying at a speed of up to 4800 meters a second, and a distance of up to 250 km. The S-400 is also capable of tracking and launching against most stealth technology.