In an interview last week, President Trump called Kim Jong Un a "smart guy" and said he would reach out to the North Korean leader.

North Korean leader Kim Jong Un inspected a facility that produces nuclear material and called for bolstering the country’s nuclear fighting capability, state media reported Wednesday, as the

South Korea 's Yonhap News Agency said North Korea might be using a vertical cold-launch system to fire the missiles. The system, which is commonly associated with submarine- and ship-based weapons, ejects a missile from its container before the missile ignites midair.

North Korea conducted another missile test while issuing a stern message to the United States. The test of a underwater-to-surface cruise missile comes just weeks after the country claimed to test a new hyper-sonic missile.