Iran has not credibly answered the UN nuclear watchdog's long-standing questions on the origin of uranium particles found at three undeclared sites despite a fresh push for a breakthrough, the agency said in a report seen by Reuters on Monday.
The lack of progress could set up a new diplomatic clash with the West when the International Atomic Energy Agency's 35-nation Board of Governors meets next week. If Western powers seek a resolution criticizing Tehran it could deal a further blow to stalled efforts to revive the 2015 nuclear deal.
