The Russian military on Monday launched sweeping military manoeuvers in the Arctic and other areas, a show of force ordered by President Vladimir Putin amid spiralling tensions with the West over Ukraine.
The five-day Arctic drills involving 38,000 servicemen, more than 50 surface ships and submarines and 110 aircraft are intended to check the readiness of Russia's Northern Fleet and the military's ability to deploy additional forces from central Russia.
Defence Minister Sergei Shoigu said "the new challenges and military threats require further increase of the armed forces' capabilities."
As part of the exercise the military will check its ability to beef up its forces on the Arctic Novaya Zemlya and Franz Josef Land archipelagos and protect the state borders on land, in the air and at sea, Shoigu said in televised remarks.
Other tasks will include the airlifting of special operations forces to distant locations and efforts to counter the enemy's diversions.
The military elsewhere in Russia also launched drills. About 3,000 troops drilled on Sakhalin Island, the Kamchatka Peninsula and other areas in the far east.
In southern Siberia, the Russian air force launched manoeuvers at the firing range in Buryatia, and in southwestern Russia, about 500 troops were involved in tactical drills on shooting ranges in the Stavropol region.
The war games come as Russia-West ties are strained over the Ukrainian crisis and the West is also boosting its military preparedness. The United States is planning to conduct joint exercises with forces from Estonia, Latvia and Lithuania later this month.
Putin, speaking in a documentary broadcast by state television late Sunday, said that Russia was ready to bring its nuclear weapons into a state of alert during last year's tensions over the Crimean Peninsula and the overthrow of Ukraine's Moscow-friendly president.
Russian forces quickly took over Crimea following the ouster of President Viktor Yanukovych, blocking Ukrainian troops at their bases and setting the stage for a hastily called referendum on secession. Russia then annexed Crimea on March 19, 2014.