A force of 1,970 military personnel, 90 armoured personnel carriers, and 380 other pieces of equipment is set to be deployed to Nagorno-Karabakh.
The core of the peacekeeping contingent will be made up of units from the 15th Separate Motorised Rifle Brigade of the nation's Central Military District.
Russia started transferring peacekeepers and equipment at around 03:00 am GMT Tuesday, using Il-76 heavy military transport aircraft that took off from the Ulyanovsk-Vostochny airfield.