Former Russian President Dmitry Medvedev on Thursday told US President Donald Trump to remember that Moscow possessed Soviet-era nuclear strike capabilities of last resort after Trump told Medvedev to “watch his words”.

Trump, in a post on his Truth social network in the early hours of Thursday, singled out Medvedev, who is deputy chairman of Russia’s Security Council, for sharp criticism after Medvedev said that Trump’s threat of hitting Russia and buyers of its oil with punitive tariffs was “a game of ultimatums” and a step closer towards a war between Russia and the United States.

“Tell Medvedev, the failed former President of Russia, who thinks he’s still President, to watch his words. He’s entering very dangerous territory!,” Trump wrote, in his second warning to the close ally of President Vladimir Putin in recent weeks.

Trump on July 29 said Russia had “10 days from today” to agree to a ceasefire in Ukraine or be hit, along with its oil buyers, with tariffs. Moscow, which has set out its own terms for peace, which Kyiv says amount to demanding its capitulation, has not so far indicated it will comply with Trump's deadline.

Trump in his post on Thursday said he didn’t care what India - one of Russia’s biggest oil buyers along with China - did with Russia.

“They can take their dead economies down together, for all I care. We have done very little business with India, their Tariffs are too high, among the highest in the World. Likewise, Russia and the USA do almost no business together. Let’s keep it that way,” he said.

‘THE FABLED DEAD HAND’

Medvedev said that Trump’s statement showed that Russia should continue on its current policy course.

“If some words from the former president of Russia trigger such a nervous reaction from the high-and-mighty president of the United States, then Russia is doing everything right and will continue to proceed along its own path,” Medvedev said in a post on Telegram.

Trump should remember, he said, “how dangerous the fabled ‘Dead Hand’ can be,” a reference to a secretive semi-automated Russian command system designed to launch Moscow’s nuclear missiles if its leadership had been taken out in a decapitating strike by a foe.

Medvedev has emerged as one of the Kremlin's most outspoken anti-Western hawks since Russia sent tens of thousands of troops into Ukraine in 2022. Kremlin critics deride him as an irresponsible loose canon, though some Western diplomats say his statements give a flavour of thinking in senior Kremlin policy-making circles.

Trump also rebuked Medvedev in July, accusing him of throwing around the “N (nuclear) word” after the Russian official criticised US strikes on Iran and said “a number of countries” were ready to supply Iran with nuclear warheads.

“I guess that’s why Putin’s ‘THE BOSS’”, Trump said at the time.