Russia has abandoned a long-held nuclear "freeze" after Donald Trump deployed submarines near Vladimir Putin's coasts. Moscow has said it no longer considers itself bound by a self-imposed ban on the deployment of missiles - and is poised to bring short- and intermediate-range nuclear weapons into action.

Russia urged caution after Trump claimed he redeployed nuclear subs in response to provocative remarks by a senior Russian official.

The Kremlin has tried to calm tensions in a feud between Trump and Medvedev that spiraled into nuclear threats.