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.

IAEA Director General Rafael Grossi looks on during a doorstep with Austrian Chancellor Christian Stocker, Austrian Vice-Chancellor Andreas Babler and Austrian Foreign Minister Beate Meinl-Reisinger at the Austrian Chancellery in Vienna,