North Korean leader Kim Jong Un vowed to enhance his nuclear arsenal in more “practical and offensive” ways as he met with senior military officials to discuss the country’s war preparations in the face of his rivals’ “frantic” military exercises, state media said Tuesday. The meeting of the ruling Workers’ Party’s Central Military Commission on Monday came amid heightened tensions as the pace of both the North Korean weapons demonstrations and the U.S.-South Korean joint military drills have intensified in recent weeks in a cycle of tit-for-tat.