U.S. President Donald Trump has warned Iran with new and serious consequences, unless all unjustly imprisoned American citizens are released and returned. New punitive measures will be applied against Iran if the nation’s leaders do not send home all US nationals, reports the Sputnik. “For nearly 40 years, Iran has used detentions and hostage taking as a tool of state policy, a practice that continues to this day to with the recent sentencing of Xiyue Wang to ten years in prison,” the White House said in a statement. Wang , 37, a Chinese-born American was recently charged with espionage. “President Trump urges Iran to return Robert Levinson home,” the statement noted Levinson worked for the FBI before retiring in 2007, the same year he traveled alone to Iran.