Diplomats from United States, South Korea and Japan discuss North Korea threat

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

Before flying to Seoul for talks with South Korean vice foreign minister Lim Sung-nam, US deputy secretary of state John Sullivan and Japanese deputy foreign minister Shinsuke Sugiyama met in Tokyo on Tuesday and vowed to find more ways to apply pressure on Pyongyang.