Does the US have an answer to Putin's 'invincible nuke'?

Just days ahead of his re-election, Russian President Vladimir Putin made an extraordinary announcement that quickly made headlines all around the world: Russia has developed a new arsenal of next-generation nuclear weapons capable of completely bypassing all U.S. defenses.

According to the Russian leader’s two-hour State of the Nation speech, one of these weapons is an “invincible” cruise missile that can deliver a nuclear warhead to any target without being detected.