VIENNA: Iran has deepened a key breach of its 2015 nuclear deal, enriching uranium with a larger number of advanced centrifuge machines in an underground plant as it faces off with the new U.S. administration on salvaging the accord.
Tehran has recently accelerated its breaches of the deal, raising pressure on U.S. President Joe Biden as both sides say they are willing to come back into compliance with the badly eroded agreement if the other side moves first.
Iran began its breaches in 2019 in response to Washington’s withdrawal in 2018 under then-President Donald Trump and the reimposition of U.S. economic sanctions against Tehran that were lifted under the deal.
The accord says Iran can refine uranium only at its main enrichment site – an underground plant at Natanz – with first-generation IR-1 centrifuges. Last year Iran began enriching there with a cascade, or cluster, of much more efficient IR-2m machines and in December said it would install three more.
“Iran has…