Russia's Baltic Fleet started naval exercises in the Baltic Sea on Monday, the Russian military's press service said.
On the NATO side, 6,000 personnel, 50 ships and more than 45 aircraft are taking part, with Finland participating for the first time as an alliance member, the United States Navy said.
The Russian military said up to 40 ships and boats, 25 aircraft and around 3,500 personnel will take part in its exercises, which are scheduled to last until June 15.
Moscow also began drills in the Sea of Japan and far eastern Sea of Okhotsk on Monday, which will involve over 60 warships and support vessels from its Pacific Fleet.
