During the peace negotiations in Islamabad over the weekend, the United States asked Iran for a 20-year suspension of uranium enrichment. The Iranians, in a formal response sent on Monday, said they would agree to up to five years, according to two senior Iranian officials and one U.S. official. Trump has rejected that offer, the U.S. official said.
The official said the U.S. has also asked Iran to remove highly enriched uranium from the country, and the Iranians have insisted the fuel stays inside Iran. But they have offered to dilute it significantly, so that it could not be used to produce a nuclear weapon. (The risk is that the Iranians would still have possession of the fuel and in the future might be able to re-enrich it to bomb grade.)
There are also discussions of holding another round of in-person negotiations, but officials say no plans have been finalized.