Russia plans to upgrade its fleet of Antei-class nuclear-powered missile submarines with Kalibr long-range cruise missiles, Sputnik reported, citing Deputy Defense Minister Yuri Borisov.

Defense Minister Sergei Shoigu earlier said that high-precision weapons like the Kalibr missile system (NATO designation: SS-N-27A “Sizzler”) will eventually become the main element of Russia’s ability to deter a potential aggressor.

“The Zvezda Shipyard is radically modernizing the Project 949A nuclear submarines to carry Kalibr cruise missiles and installing new systems of navigation and life-support,” Borisov said during a visit to Far Eastern facility.

Project 949A Antey submarines displace 24,000 tons of water, are 154 meters long, 18 meters wide, have maximum submerged speed of up to 32 knots and can dive to 600 meters.

Designed to destroy enemy aircraft carriers, Antey subs are currently armed with six Granit cruise missiles and as many torpedo tubes.

The Kalibr-class cruise missiles were first used in combat in October 2015, when the Gepard-class frigate Dagestan, part of the Caspian Flotilla, and three other Russian Navy corvettes launched 26 Kalibr-class cruise missiles from the Caspian Sea at 11 targets in Syria as part of Russia's aerial campaign against terrorists.

Kalibr-class cruise missiles, the game-changing development by the Russian defense industry, can travel 50 to 150 meters above the ground and hit sea targets up to 350 kilometers away and ground targets more than 2,500 kilometers away.

Their maximum deviation from the designated target is only three meters.