The head of the UN’s nuclear watchdog says US strikes on Iran fell short of causing total damage to its nuclear program and that Tehran could restart enriching uranium “in a matter of months,” contradicting President Donald Trump’s claims the US set Tehran’s ambitions back by decades.

The assessment widens the divide with President Trump, who has claimed that Tehran has given up its nuclear ambitions after a U.S. attack.

Iran has the capacity to start enriching uranium again in a ‘matter of months,’ according to Rafael Grossi, the head of the International Atomic Energy Agency. Grossi’s assertion contradicts U.S. President Donald Trump’s claim that Iran’s nuclear facilities were ‘totally obliterated’ by American strikes earlier last week.