Putin Says Direct Western Intervention in Ukraine Risks a Nuclear Conflict

President Vladimir V. Putin of Russia said the West faced the prospect of nuclear conflict if it intervened more directly in the war in Ukraine, using an annual speech to the nation on Thursday to escalate his threats against Europe and the United States.

Mr. Putin said Western countries that are helping Ukraine strike Russian territory, and have discussed the possibility of sending troops from NATO countries to Ukraine, “must, in the end, understand” that “all this truly threatens a conflict with the use of nuclear weapons, and therefore the destruction of civilization.”

“We also have weapons that can strike targets on their territory,” Mr. Putin said. “Do they not understand this?”

The United States and other Western governments have largely tried to distance themselves from Ukrainian strikes on Russian territory, and comments by President Emmanuel Macron of France this week about the possibility of Western troops being sent to Ukraine drew quick rebukes from other Western officials who have ruled out such deployments.

The Kremlin said this week that dispatching contingents of troops from NATO countries to Ukraine would lead to the “inevitability” of a direct conflict between Russia and the Western alliance.

“We remember the fate of those who once sent their contingents to the territory of our country,” Mr. Putin said, an apparent reference to the invasions of Hitler and Napoleon. “But now the consequences for potential interventionists will be much more tragic.”

Mr. Putin’s comments on Thursday came in the opening minutes of his annual state-of-the-nation speech, a keystone event in the Kremlin calendar in which the president declares his plans and priorities in a televised address to hundreds of officials, lawmakers and other members of Russia’s ruling elite.

This year, the speech took on added significance because of Russia’s presidential elections scheduled for March 15-17, in which Mr. Putin is running for another six-year term. He is assured of winning, but the Kremlin has mounted a concerted publicity campaign ahead of the vote, seeking to use it as a stamp of public approval for Mr. Putin’s rule, and by extension, his war.

Mr. Putin has repeatedly made veiled nuclear threats against the West since he launched his full-scale invasion of Ukraine two years ago, seeking to leverage Russia’s enormous nuclear arsenal to deter Europe and the United States from supporting Ukraine.

He had appeared to dial down that rhetoric in the past year. But on Thursday, he returned to it, coupling his threats with a claim that he was ready to resume arms-control negotiations with the United States — but only, he suggested, if Washington was ready to discuss the war in Ukraine as well.

“Russia is ready for a dialogue with the United States on matters of strategic stability,” Mr. Putin said, a reference to arms-control talks with Washington that had been briefly underway before Russia’s invasion.

In an apparent reference to Ukraine, Mr. Putin added: “This must, naturally, be done only as a single complex, including all those aspects that affect the security of our country.”

The White House, for its part, has rebuffed Mr. Putin’s efforts to put the United States at the center of any negotiations about the war in Ukraine. American officials have said that the United States has not and will not negotiate on behalf of Ukraine.