U.S. National Security Adviser John Bolton meanwhile.... has reaffirmed that the U.S. won't back down on its stance of complete, verifiable and irreversible denuclearization of North Korea.<br />Here's our Kim Mok-yeon with more. <br /> U.S. National Security Adviser John Bolton has said that he's trying to stay optimistic and realistic at the same time, following North Korea's summit cancellation threat.<br />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 the complete, verifiable and irreversible denuclearization of North Korea. <br /> He added that during the recent inter-Korean summit, North Korean leader Kim Jong-un agreed to denuclearize, and if Pyongyang changes its mind, the U.S. will find out and the scheduled summit in Singapore will be "pretty short".<br />The U.S. official also said that he has spoken to his South Korean counterpart, Chung Eui-yong on the possible reasons behind North Korea's sudden about turn.<br /> The remarks come after the North's vice foreign minister, Kim Kye-gwan threatened that if Washington continues pushing the North to unilaterally get rid of its nuclear weapons, Pyongyang will not show up to the summit table.<br /><br />Kim Mok-yeon, Arirang News. <br />
