A total of 20 Russian warships and supporting vessels have entered the designated areas of the Baltic Sea to conduct exercises, Russia's Western Military District said in a statement on Monday.

The ships from the Russian Baltic Fleet, forming in several tactical groups, will carry out anti-submarine, air defense and mine-sweeping tasks, the statement said.

The drills are being held at a time when the North Atlantic Treaty Organization (NATO) is putting forces on standby and sending additional ships and fighter jets to Eastern Europe as tensions in and around Ukraine have escalated.

Earlier on Monday, Kremlin spokesman Dmitry Peskov said that it is impossible for the Russian military to ignore an increase in NATO military activities in Eastern Europe.