US National Security Advisor Jake Sullivan said on Sunday that the US would respond decisively to any Russian use of nuclear weapons against Ukraine, and that it had spelled out to Moscow the “catastrophic consequences” it would face.
The United States warned on Sunday of "catastrophic consequences" if Moscow were to use nuclear weapons in Ukraine, after Russia's foreign minister said regions holding widely-criticized referendums would get full protection if annexed by Moscow.
Votes in four eastern Ukrainian regions, aimed at annexing territory Russia has taken by force, were staged for a third day on Sunday. The Russian parliament could move to formalize the annexation within days.
By incorporating the areas of Luhansk, Donetsk, Kherson and Zaporizhzhia into Russia, Moscow could portray efforts to retake them as attacks on Russia itself, a warning to Kyiv and its Western allies.
U.S. National Security Adviser Jake Sullivan said on Sunday the United States would respond to any Russian use of nuclear weapons against Ukraine and that it had spelled out to Moscow the "catastrophic consequences" it would face.
"If Russia crosses this line, there will be catastrophic consequences for Russia. The United States will respond decisively," Sullivan told NBC's "Meet the Press" television program.
The latest U.S. warning followed a thinly veiled nuclear threat made on Wednesday by President Vladimir Putin, who said Russia would use any weapons to defend its territory.
Foreign Minister Sergei Lavrov made the point more directly at a news conference on Saturday after a speech to the U.N. General Assembly in New York in which he repeated Moscow's false claims to justify the invasion that the elected government in Kyiv was illegitimately installed and filled with neo-Nazis.