Iran has the capacity to start enriching uranium again - for a possible bomb - in "a matter of months", the head of the UN's nuclear watchdog has said, BBC reported.

Rafael Grossi, head of the International Atomic Energy Agency (IAEA), said the US strikes on three Iranian sites last weekend had caused severe but "not total" damage, contradicting Donald Trump's claim that Iran's nuclear facilities were "totally obliterated".

"Frankly speaking, one cannot claim that everything has disappeared and there is nothing there," Grossi said on Saturday.

Israel attacked nuclear and military sites in Iran on 13 June, claiming Iran was close to building a nuclear weapon, according to BBC.