Diplomats from Washington, Seoul, Tokyo talk N. Korea threat

Diplomats from the United States, South Korea and Japan are meeting in Seoul to discuss policy responses to North Korea's accelerating efforts to expand its nuclear weapons program.

U.S. Deputy Secretary of State John Sullivan and Japanese Deputy Foreign Minister Shinsuke Sugiyama vowed to find more ways to apply pressure on Pyongyang after a meeting in Tokyo before they flew to Seoul for talks with South Korean Vice Foreign Minister Lim Sung-nam on Wednesday.

The talks come as the United States and South Korea hold joint naval drills to train for potential North Korean provocations.

North Korea has recently tested purported thermonuclear weapons and long-range missiles and flew two midrange missiles over Japan between threats to fire the same weapons toward Guam, a Pacific U.S. territory and military hub.