U.S. national security adviser Jake Sullivan said this on Friday, Ukrinform reports, citing CNN.
"Meaning we will elect the form and nature of our response based on the nature of the action Russia takes and we'll do so in coordination with our allies," Sullivan said.
According to him, the United States has warned Russia that there will be a severe price if the Russians use chemical weapons.
"And I won't go beyond that other to say the United States has no intention of using chemical weapons under any circumstances," Sullivan said.
Biden said in Brussels on Thursday that the United States and NATO would respond proportionally to the possible use by Russia of chemical arms and other weapons of mass destruction in Ukraine. Biden's brief answer raised questions about the nature of the U.S. response and whether this will envisage the use of the same weapons against Russia.