Russia is developing new nuclear weapons that are immune to enemy interception, Vladimir Putin has claimed.
The Russian President said this includes a nuclear-powered cruise missile and an underwater drone.
Speaking in a state-of-the-nation speech, Mr Putin warned that Moscow would regard a nuclear attack on its allies as an attack on Russia itself and would respond swiftly.
“We would consider any use of nuclear weapons against Russia or its allies to be a nuclear attack on our country. The response would be immediate,” he told Russian politicians.
Mr Putin claimed the high-speed cruise missile, which was tested late last year, has an unlimited range and can penetrate any missile defence.
The high-speed underwater drone can carry a nuclear warhead and target both aircraft carriers and coastal facilities, the president also claimed.
A new heavy intercontinental ballistic missile (ICBM) called Sarmat is also under testing and has a range and number of warheads exceeding the capabilities of its predecessor, Mr Putin added.