Vladimir Putin today declared his readiness for nuclear war should the US deploy troops to Ukraine as Moscow's fight against Kyiv rages on.

'From a military-technical point of view, we are, of course, ready,' the 71-year-old dictator declared in an interview with state-controlled Rossiya-1 television.

In unsettling comments, he reminded the state-controlled channel that Russia's nuclear doctrine permitted use of nuclear weapons in the event of a perceived threat to national security.