The U.N. nuclear agency has reported no new Iranian violations of a landmark nuclear deal Tehran signed with six world powers that limits its atomic prowess in exchange for sanctions relief.

In a confidential report obtained by The Associated Press and issued Friday, the International Atomic Energy Agency also says Iran has corrected one infringement noted in February by reducing its heavy water supply to the allowed limit of 143.3 tons or below after exceeding it earlier in the year.

Heavy water is used in reactors that produce substantial amounts of plutonium, a potential path to nuclear weapons.

Some of the excess was exported to the U.S. under an arrangement criticized by U.S. congressional opponents. Since then, the House of Congress has voted to bar future U.S. purchases.