Both Russian and American officials sounded a pessimistic note after three rounds of talks last week, with one Russian diplomat saying that talks with the West were approaching a “dead end,” and Mr. Blinken offered little reason for optimism.

Mr. Blinken said the United States did not make any formal proposals last week but merely “talked about areas” for reciprocal cooperation, including arms control and the conduct of military exercises in Europe.

He said it was unclear whether Russia was prepared to negotiate in good faith on those fronts, or at all.

Russia has positioned around 100,000 troops along its western border with Ukraine, although precise estimates vary. On Tuesday, the White House press secretary, Jen Psaki, said that Russia “could at any point launch an attack in Ukraine.”

In a news conference on Wednesday, President Biden echoed that message, saying he expected Mr. Putin to invade. “Do I think he’ll test the West, test the United States and NATO, as significantly as he can? Yes, I think he will,” Mr. Biden told reporters, adding: “But I think he will pay a serious and dear price for it that he doesn’t think now will cost him what it’s going to cost him. And I think he will regret having done it.”

Speaking at a forum in Moscow earlier on Wednesday, Russia’s deputy foreign minister, Sergei A. Ryabkov, repeated his government’s previous denial that Moscow has any plans to move its forces into Ukraine.

“We will not attack, strike, invade, quote unquote, whatever, Ukraine,” Mr. Ryabkov said. He said the Russian troops near Ukraine’s border were conducting training exercises.