Iran continues to defy UN Security Council demands to scrap its uranium enrichment program and has instead expanded its activities, the International Atomic Energy Agency said Wednesday, in a finding that sets the stage for new council sanctions. The report from Mohamed ElBaradei, the head of the UN's nuclear watchdog agency, also faulted Tehran for "blocking IAEA efforts to probe suspicious nuclear activities, saying that meant it could not provide assurances about ... the exclusively peaceful nature of its atomic program." And, in new and worrying phrasing, it expressed concern about its deteriorating understanding of unexplored aspects of the program, despite four years of a probe sparked by revelations that Tehran had been clandestinely developing enrichment and other nuclear activities that could be used to make weapons for nearly two decades.