It's the largest naval deployment since the end of the Cold War, according to a diplomat speaking to Reuters.
Russian defense officials say there are a number of heavily armed vessels already positioned in waters off the Syrian coast.
They will soon be joined by a formidable flotilla of Russia's heaviest naval armor -- now steaming through northern European seas
-- including the country's sole aircraft carrier, the recently refitted Admiral Kuznetsov.
The carrier -- the flagship of the Russian Navy -- is accompanied by submarine escorts, and at least seven other surface ships, including the giant nuclear battle cruiser, Peter the Great.
Assembling such a large Mediterranean armada sends a powerful message about Russia's military capabilities.
It remains one of the few nations able to project power globally in this way, albeit in a vastly diminished capacity compared to the old Soviet Union.
Of course, there are uncertainties.
This is the first time the Admiral Kuznetsov -- which can carry up to 50 aircraft including strike planes and helicopter gunships -- has been deployed on a combat mission.
A naval tug boat routinely accompanies the 31-year-old ship, which has been dogged by mechanical failures in recent years.
So far, Russian naval power has played a limited role in the Syrian conflict.
There have been missiles fired from Russian ships in the remote Caspian Sea and from the Mediterranean.
But these naval strikes have made up only a tiny fraction of the intense bombardment carried out by Russian forces in Syria, most of which have been conducted by land-based aircraft.
That could soon change.
Analysts say the deployment of such a large naval task force implies that Russia -- a major arms exporter -- wants to put its own sea power to the test.
Syria has often been used as a proving ground for Russian weaponry. Its latest combat aircraft have seen action there, as have advanced anti-aircraft systems and newly-developed cruise missiles.
According to Russian state media, defense officials say
the Syrian conflict has revealed "some design and production flaws in Russian combat hardware," which are now being addressed.
The concern among Western observers is that Russia is now building up its naval forces in the eastern Mediterranean ahead of a possible major assault on rebel positions in Syria.
The NATO Secretary General, Jens Stoltenberg, warns the Russian "carrier group may be used to increase attacks on Aleppo."
"That's something very different than to deploy a carrier group to the Mediterranean as part of a normal deployment, which we have seen before," he said
For the moment, there is a fragile humanitarian pause in fighting, with Russian and Syrian forces unilaterally suspending their attacks on Aleppo to allow civilians and fighters to leave.
But once the Russian fleet arrives, Moscow will have the firepower to push for a decisive military victory.