President Vladimir Putin warned the West on Wednesday that Russia could use nuclear weapons if it was struck with conventional missiles, and that Moscow would consider any assault on it supported by a nuclear power to be a joint attack.

MOSCOW (AP) — Russian President Vladimir Putin said Wednesday that a nuclear power supporting another country’s attack on Russia will be considered a participant in aggression under a new version of Moscow’s nuclear doctrine.

President Vladimir Putin will chair a meeting of Russia's Security Council on nuclear deterrence on Wednesday as Moscow weighs a response to Ukraine's requests that the U.S. allow it to strike deep into Russia with long-range Western missiles.