South Korea will use next year\'s world nuclear security summit in Seoul to increase diplomatic pressure on North Korea to abandon its atomic arsenal, a key organizer said Wednesday. The Nuclear Security Summit will be held in Seoul on March 26 and 27, attended by top leaders from about 50 countries, including the United States, Russia, China, Japan, Britain and France. It will be the second of its kind after the inaugural meeting in the U.S. last year.