MOSCOW — President Biden and President Vladimir V. Putin of Russia talked by phone Tuesday for the first time since Mr. Biden’s inauguration, and the Kremlin said the two leaders agreed to extend the last remaining nuclear arms treaty between their countries, which expires next month.
Mr. Putin congratulated Mr. Biden, a Kremlin statement on the call said, and discussed Ukraine, Iran and the possibility of a summit meeting of the permanent members of the United Nations Security Council. The Kremlin’s description of the call did not mention the Russian opposition leader Aleksei A. Navalny, whose arrest on Jan. 17 sparked protests across the country last weekend.
“In all, the conversation of the leaders of Russia and the United States was businesslike and frank,” the Kremlin said. Mr. Putin, the Kremlin said, “noted that normalizing the relationship between Russia and the United States would be in the interest of both countries and — given their special responsibility for security and stability in the world — of the entire international community.”
The White House confirmed the phone call in a statement that said Mr. Biden had raised Mr. Navalny’s situation in the conversation and had agreed with Mr. Putin to “work urgently to complete the extension” of the nuclear treaty, which expires Feb. 5.
“President Biden made clear that the United States will act firmly in defense of its national interests in response to actions by Russia that harm us or our allies,” the White House statement said. “The two presidents agreed to maintain transparent and consistent communication going forward.”
The New Start treaty is an Obama-era accord that limits the Russian and American strategic nuclear arsenals to 1,550 warheads and bombs each. It contains a provision for a five-year extension if both sides agree — a move that Mr. Putin has favored but that the Trump administration did not agree to. Mr. Biden decided to seek the five-year extension shortly after he took office last week, arguing that doing so could prevent a nuclear arms-race at a time of competition and confrontation with Moscow around the world.
Mr. Putin and Mr. Biden “voiced their satisfaction” about diplomatic steps taken earlier in the day to exercise the extension, the Kremlin said.
“In the coming days, both sides will finish the procedures necessary to assure the continued functioning of this important international legal mechanism to place mutual limits on nuclear-missile arsenals,” the Kremlin said.