U.S. Defense Secretary Robert Gates, left, arrives to sign the guest book before meeting South Korean Prime Minister Chung Un-chan as U.S. Ambassador to South Korea Kathleen Stephens looks on at the Government Complex in Seoul, South Korea, Wednesday, Oct. 21, 2009. Gates said Wednesday the United States will never accept a North Korea with atomic bombs, saying the communist regime poses threats "even more lethal and destabilizing" than before.