Vladimir Putin’s security chief issued a chilling warning about Russia’s ‘dead hand’ nuclear capability as he sparred with Donald Trump in an increasingly tense war of words.

Dmitry Medvedev, who serves on the country’s Security Council, said the US president should ‘recall his favorite movies about “the walking dead” and remember how dangerous the so-called ‘dead hand’ … could be.’

Trump ordered the deployment of a pair of US nuclear submarines after the former Russian president made the sinister threat. 

‘We had to do that. We just have to be careful,’ Trump said on the White House lawn on Friday. ‘A threat was made and we didn’t think it was appropriate. So I have to be very careful.

‘A threat was made by a former president of Russia, and we’re going to protect our people.’ 

The ‘dead hand’ is Russia’s rumored world-ending nuclear weapon. It takes its name because it supposedly does not need any command from an actual human, leaving the country with the ability to retaliate even if its leadership and military forces are wiped out, according to Military.com. 

The automatic nuclear weapons control system called Perimeter, is connected to thousands of Russia’s nuclear weapons, reportedly including hypersonic missiles. 

Russian Strategic Missile Forces General Sergey Karakaev confirmed to a Russian newspaper that the Cold War technology existed in 2011 and warned it could wipe out the entire US in a mere 30 minutes. 

The US has a similar system of sensors that monitor radiation to track any incoming missiles, but has never developed an automatic trigger, which might explain Trump’s protective military move on Friday. 

‘I have ordered two nuclear submarines to be positioned in the appropriate regions, just in case these foolish and inflammatory statements are more than just that,’ Trump wrote on Truth Social on Friday afternoon.

‘Words are very important, and can often lead to unintended consequences, I hope this will not be one of those instances. Thank you for your attention to this matter!’

Medvedev, the former president of Russia who stepped down when Vladimir Putin returned to power, drew Trump’s ire with his own post this week. 

‘Trump’s playing the ultimatum game with Russia…Each new ultimatum is a threat and a step towards war. Not between Russia and Ukraine, but with his own country. Don’t go down the Sleepy Joe road!’ he wrote.

The war of words began after Trump gave Russia a new deadline to end the war in Ukraine.  

Tensions ramped up after Trump announced he was moving up his ultimatum for Russia to agree to end the war by August 8. 

Previously, Trump has threatened a 10 or 12-day deadline, and promised to impose severe tariffs on the country’s oil and other exports if President Vladimir Putin didn’t end the war in 50 days.  

On Thursday, Trump tore into Medvedev, calling him a ‘failed’ president ‘who thinks he’s still president’, and told him to ‘watch his words’. 

‘He’s entering very dangerous territory,’ Trump wrote. 

Trump’s jabs at Medvedev, who is often a caustic critic of US policy, allows him to steer clear of Putin – with whom Trump has shown obvious frustration in recent weeks, despite Trump often referring to him as someone he can ‘get along with’. 

Trump has lamented apparently positive phone conversations with Putin followed within hours by Russian attacks on Ukrainian cities and towns.

Trump’s threats come after Russia launched yet another devastating attack on Kyiv this week, which killed dozens of people, including a six-year-old boy.

Russia has routinely been sending swarms of hundreds of drones to attack Ukraine, with houses and apartment buildings suffering regular blasts.

An estimated 31 people were killed and 150 injured during Thursday’s attacks.