Vladimir Putin said Russia has tested new nuclear weapons which are immune to enemy interception.
The Russian president said the weapons include a nuclear-powered cruise missile and an underwater drone.
Mr Putin said in a state-of-the-nation speech that the high-speed cruise missile, tested last autumn, has an unlimited range and is capable of penetrating any missile defence.
He said the high-speed underwater drone is capable of carrying a nuclear warhead which could target both aircraft carriers and coastal facilities.
Mr Putin said Russia has also tested a new heavy intercontinental ballistic missile (ICBM), called Sarmat, with a range and a number of warheads exceeding the capabilities of its predecessor.