Biden adviser: US will ‘respond decisively’ if Russia uses nuclear weapons

White House national security adviser Jake Sullivan on Sunday said the United States will “respond decisively” if Russian President Vladimir Putin moves to use nuclear weapons. 

“We have communicated directly, privately, at very high levels, to the Kremlin that any use of nuclear weapons will be met with catastrophic consequences for Russia, that the United States and our allies will respond decisively. And we have been clear and specific about what that will entail,” Sullivan told CBS “Face the Nation” host Margaret Brennan. 

“We have, in public, been equally clear as a matter of principle that the United States will respond decisively if Russia uses nuclear weapons, and that we will continue to support Ukraine in its efforts to defend its country and defend its democracy.”

Sullivan’s comments came after Putin last week hinted at being willing to use nuclear weapons in Ukraine.

The top White House national security aide on Sunday also expressed concern over Russian military presence at the Zaporizhzhya nuclear power plant in Ukraine, the largest such plant in Europe.

“It’s been put into cold shutdown to make it less likely that there’s some kind of catastrophic incident at the plant. It’s actually still being operated by Ukrainian operators who are essentially at gunpoint from the Russia occupying forces. And the Russians have been consistently implying that there may be some kind of accident at this plant,” Sullivan said. 

Russia has held territory around the plant since early in the war, and nearby shelling has heightened international concern about a potential nuclear accident.

The United Nations’s International Atomic Energy Agency recently sent a mission to Zaporizhzhya to assess the situation at the plant and released a report noting major concerns about the lack of stability around the plant.

Sullivan on Sunday said the possible use of nuclear weapons is “a matter of paramount seriousness” that “we have to take deadly seriously.”