Vladimir Putin said Russia has tested high-tech nuclear weapons invulnerable to US missile defence in a defiant speech before he stands for re-election this month.

In a state-of-the-nation address to top officials, Mr Putin made his most forceful declaration yet of Russia's military might. He said the country was developing a new generation of deadly weapons able to penetrate missile defences, including a nuclear-powered cruise missile with “unlimited range,” an underwater nuclear drone and a “practically invulnerable” hypersonic warhead that travels “like a ball of fire”.

Moscow has also tested its long-awaited Sarmat heavy intercontinental ballistic missile, which will fly farther and carry more warheads than its predecessors, he said.

“Russia remained a nuclear power, but no one wanted to speak with us. No one wanted to listen to us. Listen to us now,” Mr Putin said to enthusiastic applause from the audience.