Iran has begun using advanced centrifuges at the Fordow nuclear facility to enrich uranium to 20%, the International Atomic Energy Agency (IAEA) reported on Wednesday.
According to the IAEA, Iran has begun feeding uranium hexafluoride feedstock, which is enriched to 5% purity, into a cascade of 166 IR-6 centrifuges at Fordow.
The news comes two days Iran and Western powers resume the long-stalled negotiations over Iran's nuclear program in Vienna.
The 2015 Iran nuclear deal only allows Iran to enrich uranium with relatively antiquated first-generation IR-1 centrifuges at the underground Fuel Enrichment Plant (FEP) at Natanz. However, Iran has consistently scaled back its compliance with the deal since former US President Donald Trump withdrew from the agreement in 2018.