Any hopes of reviving the highly polarized Iran nuclear deal are just about dead now. The Chairman of Iran’s Atomic Energy Organization announced Tuesday his country will start enriching uranium at its underground Fordo site to 60%.

Before the Iran nuclear deal, officially called the Joint Comprehensive Plan of Action (JCPOA), Iran was enriching uranium to 20%. Far below the 90% needed for a nuclear bomb.

Under the JCPOA, Iran received sanctions relief in exchange for capping enrichment at 3.67%. But former President Donald Trump pulled the U.S. out of the deal in 2018. The U.S. reimposed sanctions on Iran at that time. As a result, Tehran also backed away from its part of the agreement.

Since then, Iran blocked the UN’s International Atomic Energy Agency from inspecting its nuclear sites and removed monitoring equipment. Last week, the IAEA passed a resolution ordering Iran to comply with its investigation into nuclear material at undeclared sites in Iran.

However, the UN has no means of enforcing any orders on Iran. As a response to the order, which Iranian leaders called “politically motivated,” Iran said it will not only enrich uranium to 60% at Fordo, but it would also install newer centrifuges at the site.

Iran already enriched uranium to 60% purity at its other nuclear sites. In July, the IAEA reported Iran had 43 kilograms of uranium enriched to 60% purity. If Iran enriched that uranium a little more, it’s enough material for one nuclear weapon.

Indirect talks between the U.S. and Iran to revive the JCPOA are at a standstill as both sides demand more flexibility.

Reuters contributed to this report.