North Korea's Kim warns Seoul's nuclear-powered submarine plan will 'worsen instability'

North Korean leader Kim Jong-un has said South Korea's plan to build nuclear-powered submarines will "worsen the instability" in the region, calling Seoul's move a threat to the North's national security, according to state media Thursday. Kim made the remarks during an on-site inspection of an 8,700-ton nuclear-powered strategic guided missile submarine under construction, the Korean Central News Agency (KCNA) said. The North Korean leader referred to Seoul's plan to build nuclear-powered subma