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.

Iran could be producing enriched uranium in a few months, the head of the U.N. nuclear watchdog Rafael Grossi was quoted as saying on Sunday, raising doubts about how effective U.S. strikes to destroy Tehran's nuclear programme have been.

Iran likely can resume uranium enrichment to make a nuclear bomb in a few months, despite damage to nuclear facilities by United States and Israel airstrikes, the United Nations' nuclear watchdog chief said.