Iran Says U.N. Nuclear Ban 'Illegal' TEHRAN, Iran - Iran said Sunday that demands from the U.N. atomic watchdog agency that it freeze all work on uranium enrichment - technology that can be used for nuclear weapons - were "illegal."   Hasan Rowhani, Iran's top nuclear negotiator, said at a news conference that his country would nonetheless continue with its voluntary suspension of what he described as "actual enrichment" - the injection of uranium gas into centrifuges...