The Bulava missile, designed for Russia’s fleet of ballistic missile-carrying Borei-class nuclear submarines, is capable of delivering up to 10 nuclear warheads at a range of 8,000 kilometers. Russia has been paying ever greater attention to bolstering its nuclear deterrent in recent years as the United States works to deploy anti-ballistic missile defenses in Europe.

The Russian Navy test-launched four intercontinental ballistic missiles (ICBM) from a nuclear-powered submarine in the White Sea on Tuesday.

Four Bulavas reached their practice targets in the Far East after being launched from a submerged position in the White Sea, the Navy said Wednesday.

“It was the first-ever salvo fire from this type of submarine,” the Navy’s Northern Fleet said in an online statement, referring to the Borei-class Yury Dolgoruky, a nuclear-powered boat commissioned in 2014.

The Borei-class Yury Dolgoruky, part of Russia's nuclear modernization effort intended to revitalize a fleet of aging and generally neglected Soviet-built nuclear missile submarines, can reportedly carry up to 16 Bulavas.

The Russian Navy’s Northern Fleet said the latest test confirmed the combat readiness of the ICBMs and the submarines.

The Bulava development program has experienced problems in previous years, including failed launches in 2013 and 2016.