Though Iran has yet to say officially what exact steps it will take as a deadline it gave Europeans to salvage the deal is to expire on Friday. Centrifuges that speed enrichment further shorten the time Tehran would need to have enough material available to build a nuclear weapon — if it chose to do so.

Under the deal, which has steadily unraveled after President Donald Trump’s unilateral withdrawal of the U.S. from the accord last year, experts thought Iran would need about a year to reach that point.

Iran’s atomic energy agency was to make an announcement on Saturday detailing its next step, which President Hassan Rouhani described as highly significant, according to the semi-official Tasnim news agency and other Iranian media. The details would be unveiled at a press conference in Tehran, the reports said.