In a fiery speech before world leaders at the U.N. on Saturday, North Korea's foreign minister vowed the country will take "merciless pre-emptive action" if it detects U.S. or allied military action against it.
Just hours earlier, U.S. warplanes flew in international airspace to the farthest point north of the two Koreas' border that any such American aircraft has gone this century.
In his highly anticipated speech before world leaders at the United Nations General Assembly, Foreign Minister Ri Yong Ho derided U.S. President Donald Trump as "a mentally deranged person full of megalomania and complacency" with his finger on the "nuclear button."