France's foreign ministry on Thursday called on Iran to refrain from any concrete action that does not comply with its 2015 nuclear deal obligations after Tehran said it would develop centrifuges for faster uranium enrichment.
"Iran must refrain from any concrete action that is not in line with its commitments and that may hinder de-escalation efforts," Foreign Ministry spokeswoman Agnes von der Muhll told reporters in a daily online briefing.
She added that Paris would study the Iranian announcement with its partners and the UN atomic agency.
Though Iran has yet to say officially what exact steps it will take as a deadline it gave Europeans to salvage the nuclear 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 US 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 Iranian President Hassan Rouhani described as highly significant.
Iran has begun break limits of the deal, such as just creeping beyond its 3.67%-enrichment limit and its stockpile rules. Using advanced centrifuges speeds up enrichment and Iranian officials already have raised the idea of enriching to 20% — a small technical step from weapons-grade levels of 90%.