North Korea threatens war over sanctions

North Korea stoked regional tensions Wednesday, threatening more nuclear tests and saying additional sanctions imposed on it would be considered an act of war, as nervous neighbors raced to bolster defenses and punish Pyongyang.

South Korea said it was making sure its troops were prepared for atomic warfare, and Japan imposed new economic sanctions to hit the economic lifeline of the communist nation's 1 million-member military, the world's fifth-largest.