The concerning escalation comes after a week of talks in Geneva between the US and Russia over the Kremlin’s military aggression which failed to reach a resolution. Mr Putin has amassed more than 100,000 troops along with military equipment along the Ukrainian border, sparking fears of an invasion. Senior Washington officials have signalled that the US would be willing to support Ukraine if Russia followed through with an invasion.
Russian media analyst Julia Davis noted: “On multiple [state TV] shows, experts and pundits are claiming that the principle of mutually assured destruction (MAD) is obsolete and trying to convince the audiences that Russia could prevail over the US in a nuclear war.”
Russia currently holds the largest share of nuclear warheads in the world, according to the latest estimates from the Nuclear Information Project and the Federation of American Scientists.
Mr Putin is estimated to have a total of 6,257 warheads, with US President Joe Biden on 5,550 and Britain trailing behind with only 225.
In a hastily arranged trip, US Secretary of State Antony Blinken will visit Ukraine on Tuesday in a show of diplomatic support.
From Kiev, Mr Blinken will travel to Berlin on Thursday, where he will meet with his German, British and French counterparts to discuss a possible response to any Russian military action.
Russian Foreign Minister Sergey Lavrov told reporters on Monday that he expects a written response this week from the US and its allies to Moscow’s request for “security guarantees”.
The “security guarantees” include NATO denying membership to Ukraine and other former Soviet countries and rolling back its military deployments in Central and Eastern Europe.
Washington and its allies have repeatedly rejected these demands.
But Mr Putin has warned that Moscow will take unspecified “military-technical measures” if they continue to reject the demands.
The White House announced on Friday that US intelligence officials had concluded Russia has already deployed operatives to rebel-controlled eastern Ukraine to carry out acts of sabotage there and blame them on Ukraine to create a pretext for a possible invasion.
Senator Jeanne Shaheen, a New Hampshire Democrat currently visiting Ukraine, said: “Our bipartisan congressional delegation sends a clear message to the global community: the United States stands in unwavering support of our Ukrainian partners to defend their sovereignty and in the face of persistent Russian aggression.”
Meanwhile, Britain is supplying Ukraine with short-range anti-tank missiles for self-defence.
Defence Secretary Ben Wallace told MPs a small team of British troops would also be sent to Ukraine to provide training due to”legitimate and real cause for concern” that Russian troops could invade.
Dozens of British troops have been in Ukraine since 2015 to help train their armed forces.
The UK has also made a commitment to help rebuild Ukraine’s navy following Russia’s invasion of Crimea in 2014.
Over the last eight years, the fighting in the Crimean Peninsula has killed more than 14,000 people and devastated their industrial heartland, known as Donbas.
How the US, which just exited two decades of war in Afghanistan, might support Ukraine in military combat has not been announced.