The International Atomic Energy Agency (IAEA) has confirmed that Syria constructed an undeclared nuclear reactor in the eastern province of Deir ez-Zor under former President Bashar al-Assad, who was ousted in December 2024. In a confidential report, the UN watchdog said inspectors visited the site and found cooling infrastructure consistent with a nuclear reactor, and also uncovered a fuel fabrication plant and a storage facility for nuclear material — none of which had ever been reported to the agency. Separately, inspectors discovered a previously undeclared site containing approximately 73 tonnes of natural uranium, which has now been placed under IAEA containment and surveillance, while Syria's new government has said it welcomes international cooperation on nuclear oversight.