Under the Nuclear Non-Proliferation Treaty, Iran is legally bound to declare all nuclear material and permit IAEA inspectors to verify it is not diverted from peaceful uses.

From the articleIran hasn’t tried to repair nuclear facilities damaged in US strikes, UN nuclear chief saysAlso in Iran hasn't tried to repair nuclear facilities damaged in Israeli-U.S. strikes: IAEA chief, No sign Iran is rebuilding nuclear sites but 440 kg of uranium unaccounted for, UN watchdog says