Trump warns Iran over detained Americans: White House

U.S. President Donald Trump warned that Iran would face "new and serious consequences" unless all unjustly detained American citizens were released and returned, the White House said in a statement on Friday.Trump urged Iran to return Robert Levinson, an American former law enforcement officer who disappeared more than 10 years ago in Iran, and demanded that Tehran release businessman Siamak Namazi and his father, Baquer.The statement capped a week of rhetoric against Tehran.