Russia test-fired its new nuclear-capable Sarmat intercontinental ballistic missile as part of a broader modernization of its nuclear forces, with President Vladimir Putin calling it the world’s most powerful missile.

Putin said the missile, designed to replace the aging Soviet-era Voyevoda system, will enter combat service by the end of the year and is capable of carrying multiple warheads over extremely long distances.

The launch comes as Russia continues to emphasize its nuclear strength during the war in Ukraine and after the expiration of the last major U.S.-Russia nuclear arms treaty, raising fears of a new arms race.

Moscow has also been developing other advanced weapons, including hypersonic missiles, nuclear-powered cruise missiles, and underwater drones intended to bypass U.S. missile defenses, CBS News has reported.

At the same time, the U.S. and Ukraine are reportedly discussing a new drone defense agreement amid ongoing security tensions between Russia and the West.