UN nuclear watchdog International Atomic Energy Agency (IAEA) on Tuesday said that Iran has reversed a months-long slowdown in the rate at which it is enriching uranium to up to 60% purity, close to weapons grade.

IAEA Director General Rafael Mariano Grossi said in the report that Iran “in recent weeks had increased its production of highly enriched uranium, reversing a previous output reduction from mid-2023.”

The UN nuclear watchdog said its inspectors had verified the increased rate of production since the end of November at facilities in Natanz and Fordow to about 9 kilograms per month, up from 3 kilograms per month since June and representing a return to earlier levels of production.

“The Agency confirms that, since the end of November 2023, the rate at which Iran has been producing uranium enriched up to 60% U-235 at these two facilities combined has increased to approximately 9 kg per month,” the report to member states said.

Iran had previously slowed down the rate at which it was enriching uranium to 60% purity. Uranium enriched at 60% purity is just a short, technical step away from weapons-grade levels of 90%.

In January, Grossi had said that Iran already had enough nuclear material for several weapons. “They have amassed enough nuclear material for several nuclear weapons — not one at this point,” he said, listing 70 kilograms of uranium enriched to 60% purity and 1,000 kilograms at 20%.

Enriching uranium means increasing the percentage of uranium-235, the isotope of uranium that can be used in nuclear fission.