The United States and its European allies appear on the cusp of restoring the deal that limited Iran’s nuclear program, Biden administration officials said Monday, but cautioned that it is now up to the new government in Tehran to decide whether, after months of negotiations, it is willing to dismantle much of its nuclear production equipment in return for sanctions relief.

Speaking to reporters, a senior State Department official signaled that negotiations had reached a point where political leaders needed to decide whether they would agree to key elements of an accord that would essentially return to the 2015 deal that President Donald Trump discarded four years ago, over the objections of many of his key advisers. Ultimately, that freed Iran to resume its nuclear production, in some cases enriching nuclear fuel to levels far closer to what is needed to make nuclear weapons.

Administration officials cautioned that it was not clear whether a final agreement would be struck, and in Iran that decision is bound to go to Supreme Leader Ayatollah Ali Khamenei. And although some remain deeply skeptical that Iran would ultimately agree to the terms now being discussed, the State Department official said that "we can see a path to a deal if those decisions are made and if they are made quickly.”