North Korea says latest missile test simulated nuclear counterstrike

North Korea said Monday it simulated a nuclear attack on South Korea with a ballistic missile launch over the weekend that was its fifth missile test this month to protest the largest joint military exercises in years between the U.S. and South Korea.

The North’s leader Kim Jong Un ordered his military to hold more drills to sharpen the war readiness of his nuclear forces in the face of “aggression” by his enemies, government media reported.

The South Korean and Japanese militaries detected the short-range missile being launched Sunday into waters off the North’s eastern coast, which reportedly came less than an hour before the U.S. flew long-range B-1B bombers for training with South Korean warplanes. The North characterizes the U.S.-South Korea exercises as a rehearsal to invade, though the allies insist they are defensive in nature. Some experts say the North uses the exercises as a pretext to advance its weapons programs. Pyongyang’s official Korean Central News Agency informed the missile, which flew about 800 kilometers (500 miles), was tipped with a mock nuclear warhead. It described the test as successful, saying that the device detonated as intended 800 meters (yards) above water at a spot that simulated an unspecified “major enemy target,” supposedly reaffirming the reliability of the weapon’s nuclear explosion control devices and warhead detonators.

The report said the launch was the final step of a two-day drill that also involved nuclear command and control exercises and training military units to switch more quickly into nuclear counterattack posture, properly handle nuclear weapons systems and execute attack plans.

The exercise was also a “stronger warning” to the United States and South Korea, who are “undisguised in their explicit attempt to unleash a war” against the North, KCNA claimed. Photos published by state media showed Kim walking through a forest with his daughter and senior military officials and a missile the North described as a tactical nuclear weapon system soaring from the woods spewing flames and smoke.