Iran’s announcement that it has exceeded limits on its uranium stockpile puts it one step closer to becoming a nuclear state, shortening its breakout time to producing a nuclear weapon.

Iranian Foreign Minister Javad Zarif said Monday that Iran’s stockpile of highly enriched uranium had breached the 300-kilogram (661-pound) limit set by the 2015 nuclear agreement. Zarif said the decision was “reversible,” pending negotiations with the deal’s remaining signatories. President Trump withdrew the United States from the agreement in May 2018.