Russian President Vladimir Putin has launched the construction of new nuclear submarines and other warships, part of a sweeping military modernization effort amid tensions with the West.

He gave orders for two nuclear submarines armed with intercontinental ballistic missiles along with two diesel-powered submarines and two corvettes at shipyards in Severodvinsk, St. Petersburg and Komsomolsk-on-Amur.

The Kremlin has made military modernization a top priority as relations with the West have plunged to post-Cold War lows after Russia’s 2014 annexation of Ukraine’s Crimea.

Moscow has sought to reestablish a regular naval presence in parts of the world that the Soviet Union had during the Cold War.