Iran's stock of uranium enriched to up to 60% purity, close to weapons grade, one of the confidential International Atomic Energy Agency reports to member states showed.
The nuclear and Middle East regional elements of the understanding seem to be holding, even as the Russia-Iran part may never have been nailed down.
Israel has long instated that stiff international sanctions would help sway Tehran to abandon its program.
In the last few decades, there was a battle to stop Tehran from being able to develop a nuclear weapon.
Iran is supposed to provide access to information, locations and people, suggesting a vast improvement after years of Iranian stonewalling.