Iran has started the process of enriching uranium to 60% fissile purity at an above-ground nuclear plant at Natanz, the U.N. nuclear watchdog said on Saturday, confirming earlier statements by Iranian officials.
The move has complicated talks aimed at reviving Iran's nuclear deal with major powers as it is a big step towards producing weapons-grade uranium.
Iran had previously only reached 20% purity, and that was already a breach of the deal, which says Iran can only enrich to 3.67%.