"Russia initially earmarked just $1.2 billion for the war for all of 2016, an official familiar with the matter said. Outlays were running at about $4 million a day before Putin’s mid-November surge in troops and hardware, which doubled the cost to $8 million, or almost $3 billion on an annualized basis, according to the Royal United Services Institute, or RUSI, a military research group based in London," Bloomberg reported.

The Moscow Times earlier cited British-based IHS Jane's that the Kremlin daily spent at least $2.4 million on the military operation in Syria. However, the real costs of the operation could be doubled, hitting $4 million a day.