U.S. National Security Adviser John Bolton says he's trying to stay optimistic and realistic at the same time following North Korea's summit cancellation threat.
Speaking to Fox News Radio on Wednesday,... Bolton said the U.S. will do everything it can to have a successful meeting,... but will not back away from its objective,... which is a complete, verifiable and irreversible denuclearization of North Korea.
Bolton added he has spoken to his South Korean counterpart, Chung Eui-yong on the possible reasons behind North Korea's sudden about turn.