US President Joe Biden has said Russia is considering using biological and chemical weapons in Ukraine.
According to the AFP news agency, President Joe Biden warned Russia that the use of biological and chemical weapons would face a strong reaction from the West.
Joe Biden, referring to recent allegations by Russian President Vladimir Putin, said there was no truth in the US holding biological and chemical weapons in Europe.
In a meeting with businessmen in the capital, Washington, Biden said that Russia also believes that Ukraine has biological and chemical weapons.
"This is a clear indication that it (Russia) is considering using both (weapons)."
He said President Putin knew that having a united front of NATO member states would have serious consequences. However, Biden did not elaborate on how the allies would react.
Earlier this month, Russian officials accused Ukraine of trying to conceal US-backed chemical weapons, a claim denied by European countries, including the United States.
Following Russia's accusation, White House Press Secretary Jane Psaki tweeted that Russia was likely to use chemical and biological weapons in Ukraine following false claims, and that all countries should be vigilant.