SEOUL, South Korea (AP) — North Korea has launched its first intercontinental ballistic missile in three months after it threatened “shocking” consequences to protest alleged spying by U.S. military flights. Some experts say the launch Wednesday was likely the second test-flight of the developmental Hwasong-18 solid-fuel missile, which North Korean leader Kim Jong Un has called his most powerful nuclear weapon. South Korea and Japan assessed that the missile flew about 620 miles on a steep angle before landing between the Korean Peninsula and Japan. It came as South Korea’s and Japan’s leaders were attending the NATO summit. Some experts say the launch was meant to hone the missile technology and not directly a protest of any U.S. or South Korean action.