On Thursday, at a Democrat fundraiser in New York City, President Joe Biden claimed that Russian President Vladimir Putin was "not joking" about his "potential use of tactical nuclear weapons or biological or chemical weapons."

Biden suggested the reason for Putin's alleged willingness to risk a nuclear confrontation with the West is that "his military is, you might say, significantly underperforming."

The president told Democratic Senatorial Campaign Committee donors at James Murdoch's house, "We have not faced the prospect of Armageddon since Kennedy and the Cuban Missile Crisis."

United Nations Secretary-General António Guterres also recently employed the term "Armageddon," when in September he called for the global dismantling of nuclear warheads to prevent "humanitarian Armageddon."

White House press secretary Karine Jean-Pierre said on Tuesday that there was yet no "indication that Russia is preparing to imminently use nuclear weapons."