A near-complete nuclear reactor built secretly during the rule of toppled Syrian leader Bashar al-Assad would have been able to produce material to make nuclear weapons, the UN nuclear watchdog chief said on Monday.

Inspectors from the International Atomic Energy Agency (IAEA) last month visited two sites, one in Deir Ezzor and a second undisclosed location identified to them by Syrian authorities.

In a report seen by AFP last week, the IAEA said it found that Syria's previous government was building a nuclear reactor.

Assad was toppled in December 2024 and the current Islamist government came to power.

IAEA head Rafael Grossi said it was "obvious that the previous government was pursuing a number of clandestine" activities.