US correspondent Mark Stone says "it's pinch yourself stuff" over United States President Joe Biden talking about the issue of armageddon.

"The context to that is Vladimir Putin, the Russian leader, has been saying openly for weeks and weeks and weeks that he is prepared to use his nuclear arsenal in the war against Ukraine," Mr Stone told Sky News Australia.
"It's frightening stuff and it's fair to say we're at a moment we haven't been at since 1962 in the Cuban missile crisis."