Joe Biden
Joe Biden Jabin Botsford/Pool via REUTERS

US President Joe Biden said on Monday that Russian accusations that Kyiv has biological and chemical weapons are false and illustrate that Russian President Vladimir Putin is considering using them himself against Ukraine.

Putin's "back is against the wall and now he's talking about new false flags he's setting up including, asserting that we in America have biological as well as chemical weapons in Europe, simply not true," Biden said at a Business Roundtable event, as quoted by Reuters.

"They are also suggesting that Ukraine has biological and chemical weapons in Ukraine. That's a clear sign he's considering using both of those," he added.

Russia recently claimed that Ukraine is running chemical and biological labs with US support.

White House press secretary Jen Psaki later rejected the claims from Russia as "false" and "preposterous," and warned they could serve as a pretext for the Russians to deploy chemical weapons in their assault on Ukraine.

"It’s the kind of disinformation operation we’ve seen repeatedly from the Russians over the years in Ukraine and in other countries, which have been debunked, and an example of the types of false pretexts we have been warning the Russians would invent," Psaki said.

"Also, Russia has a track record of accusing the West of the very violations that Russia itself is perpetrating. In December, Russia falsely accused the US of deploying contractors with chemical weapons in Ukraine," she continued.

Ukrainian President Volodymyr Zelenskyy also insisted that no chemical weapons or other weapons of mass destruction were developed in his country.

"No chemical or any other weapons of mass destruction were developed on my land. The whole world knows that. You know that. And if Russia do something like that against us, it will get the most severe sanctions response," he said.