Trump administration officials want to broaden the New START accord and warn that the price of a new deal will rise after the election. Joe Biden supports a straight five-year extension of the deal.
President Trump had a pre-election plan to show he had gotten something out of his mysteriously friendly relationship with President Vladimir V. Putin of Russia.
In the weeks before the election, the two men would announce that they had reached an agreement in principle to extend New START, the last remaining major arms control agreement between the two countries. It expires on Feb. 5, two weeks after the next presidential inauguration.
Mr. Trump has long refused to sign off on a clean five-year extension of the agreement, a step both leaders could take without Senate approval. He has described the Obama-era treaty as deeply flawed — the same thing he said about the North American Free Trade Agreement and the Iran nuclear accord — because it did not cover all of Russia’s nuclear arms, or any of China’s.