FILE - In this March 16, 2016, file photo, American student Otto Warmbier, center, is escorted at the Supreme Court in Pyongyang, North Korea. Warmbier, whose parents say has been in a coma while serving a 15-year prison term in North Korea, was released and returned to the United States Tuesday, June 13, 2017, as the Trump administration revealed a rare exchange with the reclusive country. (AP Photo/Jon Chol Jin, File)