Russia said it has developed a new array of nuclear weapons that are invincible.
President Vladimir Putin made the claims as he laid out his key policies for a fourth presidential term, ahead of an election he is expected to win in 17 days' time.
The weapons he boasted of included a cruise missile that he said could "reach anywhere in the world".
He said of the West: "They need to take account of a new reality and understand ... [this]... is not a bluff."
Giving his annual state of the nation speech, Mr Putin used video presentations to showcase the development of two new nuclear delivery systems that he said could evade detection. One video graphic appeared to show missiles raining down on the US state of Florida.
One system Mr Putin described included a "low-flying, difficult-to-spot cruise missile... with a practically unlimited range and an unpredictable flight path, which can bypass lines of interception and is invincible in the face of all existing and future systems of both missile defence and air defence".
Another was a submarine-launched, long-range missile capable of delivering a nuclear warhead.
During the two-hour televised speech to a joint sitting of both houses of parliament, he said the weapons were a response to US development of its missile defence system.
The US Pentagon responded by saying: "We're not surprised by the statements and the American people should rest assured that we are full prepared."
