Iran has defied international demands to rein in its nuclear program and has increased its stockpile of uranium enriched to near weapons-grade levels, according to a confidential report by the United Nations’ nuclear watchdog seen Tuesday by The Associated Press.

Iran has agreed to stop producing uranium enriched close to the level required for nuclear weapons, according to United Nations inspectors.

Iran has offered not to expand its stock of uranium enriched to up to 60% purity, near the roughly 90% of weapons grade, and made preparations to do that, the U.N. nuclear watchdog said in confidential reports to member states on Tuesday.

Iran has taken a preparatory technical step towards curbing its production of highly enriched uranium, the head of the International Atomic Energy Agency (IAEA), Rafael Grossi, said on Tuesday, several days after his talks in Iran.

Iran is moving to stop producing enriched uranium at levels close to what is required for nuclear weapons now that it has stockpiled nearly 32 times the limit set in the 2015 nuclear deal. A 12-page report from the International Atomic Energy Agency that was reviewed by Bloomberg said that Iran has taken steps “aimed at stopping the increase of its stockpile.