North Korean leader Kim Jong Un said a U.S.-South Korea joint military exercise could "ignite a war" and called for the rapid expansion of Pyongyang's nuclear capabilities.

Kim Jong Un vows to accelerate North Korea's nuclear buildup while denouncing the South Korea-US joint military exercise.

North Korean leader Kim Jong Un called Tuesday for the "rapid expansion" of the country's nuclear weapons capability, citing ongoing US-South Korea military exercises that he said could "ignite a war".