Iran is grappling with its worst water crisis in decades, with officials warning that Tehran — a city of more than 10 million — may soon be uninhabitable if the drought gripping the country continues.

Iran still has not let inspectors into the nuclear sites Israel and the United States bombed in June, the U.N. atomic watchdog said in a confidential report on Wednesday, adding that accounting for Iran's enriched uranium stock is "long overdue".