KUHN: Japan, meanwhile, is working to make sure that its interests are still represented even though it's not at the talks. Mintaro Oba, a speechwriter and former U.S. diplomat, notes that Japan is focused on some narrow interests which are not shared by the U.S.
MINTARO OBA: One is the issue of Japanese citizens who have been abducted by North Korea in the 1970s and 1980s - a very emotional issue for the Japanese people.
KUHN: Tokyo has taken a harder line on North Korea than Seoul and enthusiastically backed U.S. sanctions against Pyongyang. Oba says this fits in with Prime Minister Shinzo Abe's aim of revising Japan's U.S.-drafted postwar constitution, especially its limitations on Japan's military.
OBA: It was in Prime Minister Abe's domestic interest to play up the North Korea threat and demonstrate the necessity of strengthening Japan's own security posture, which could include the constitutional reform that Prime Minister Abe has always wanted.
KUHN: Japan says Oba has the potential to play a key role in any deal on North Korea. It has the economic clout to help North Korea develop if it chooses to denuclearize. And if it doesn't and things take a drastic turn for the worse, then U.S. military bases in Japan will become extremely important. Anthony Kuhn, NPR News, Seoul.