The 2015 deal introduced strict limits on Iran's atomic activities in exchange for the lifting of sanctions. It slashed Iran's stock of enriched uranium, leaving it only with a small amount enriched to up to 3.67% purity, far from the roughly 90% purity that is weapons grade.

Israel has carried out attacks on Iran's nuclear facilities, alleging Tehran was getting close to obtaining a nuclear weapon.

Iran doesn’t have nuclear weapons. But it has enriched nuclear fuel to levels that put it within weeks of having enough fissile material for a bomb. Still, Iran hasn’t proved it can build a reliable nuclear device or miniaturize one to fit atop a ballistic missile.