Rafael Grossi, the director general of the International Atomic Energy Agency (IAEA), has told Fox News that the nuclear watchdog does not have “information on the whereabouts” of some 400kg of uranium that Iran has enriched to 60 per cent purity, Al Jazeera reports.

Grossi said Iranian officials had told him they would be taking protective measures, “which may or may not include moving around this material”.

“There is a question there: Where is this?” he said. “So, the way to asserting that is to allow the inspection activity to resume as soon as possible. And I think this would be for the benefit of all.”

The IAEA chief also said the US strikes on the three Iranian nuclear facilities caused “an important degree of damage”, particularly at Natanz and Isfahan.