The exercise was aimed at sharpening combined operational abilities and demonstrating the credibility of U.S. commitment to leverage its full military capabilities, including nuclear, to defend South Korea, according to Seoul’s Defense Ministry. KCNA said the launch was supervised on site by North Korean leader Kim Jong Un, who described the missile — named Hwasong-18 — as the most powerful weapon of his nuclear forces that would enhance counterattack abilities in the face of external threats created by the military activities of the United States and its regional allies.