The Biden administration dismissed on Friday a call by President Vladimir V. Putin of Russia for negotiations to end the war in Ukraine, showing no sign that flagging political support for American military aid to Kyiv had made President Biden more inclined to make concessions to Moscow.

During his two-hour interview at the Kremlin with the former Fox News host Tucker Carlson, who now broadcasts independently online, Mr. Putin offered long defenses of his invasion of Ukraine in February 2022 but said he was prepared to settle the conflict diplomatically.

“We are willing to negotiate,” Mr. Putin told Mr. Carlson in the interview, which was released on Thursday. “You should tell the current Ukrainian leadership to stop and come to the negotiating table,” he added, referring to the U.S. government.

The Russian leader spoke at a moment of apparent leverage, following the failure of a vaunted Ukrainian summer counteroffensive to achieve substantial gains and as the Biden administration is struggling to win congressional approval for desperately needed additional military aid for Kyiv.

It is not the first time Mr. Putin has expressed willingness to negotiate over the fate of Ukraine, and Western officials have long been skeptical of his intentions. But because it was his first interview with an American journalist since the invasion, his call for talks has extra resonance, analysts said.

U.S. and Ukrainian officials say that the best Ukraine’s military can hope for in the coming year, especially without more American aid, is to defend its current positions. Even so, Biden officials say they are not entertaining the idea of pressing Ukraine’s president, Volodymyr Zelensky, to negotiate with Mr. Putin.