North Korea Tests New Hypersonic Missile, Kim Vows 'Incurable Headache' for Enemies

North Korea announced Tuesday that its latest missile tests involved a new weapons system of "great significance," with state media photographs indicating the launch of a missile previously described as hypersonic.

Leader Kim Jong Un said the weapon's development would strengthen the country's war readiness and give its enemies an "incurable headache," according to the North's official Korean Central News Agency. He did not specify what the weapon was.

Kim observed Sunday's tests alongside his teenage daughter, who is widely seen as a potential successor.

South Korea's military detected North Korea firing two short-range missiles three hours apart from the eastern coastal Wonsan area on Sunday. The Joint Chiefs of Staff said the missiles flew about 450 and 600 kilometers (280 and 370 miles) toward the sea, while Japan's military said they landed in waters outside its exclusive economic zone.

The launches extended a recent run of military displays, including live-fire exercises and the commissioning of a new warship, as Kim continues to flaunt his growing nuclear program despite U.S. calls to revive diplomacy.

Following years of intensified testing, Kim now has an extensive arsenal of nuclear-capable missiles, including long-range weapons potentially capable of reaching the U.S. mainland and shorter-range systems designed to overwhelm missile defenses in South Korea and Japan.

Among the weapons North Korea has tested in recent years are various missile systems fitted with purported hypersonic weapons, designed to travel at more than five times the speed of sound. Their speed and maneuverability are intended to help them evade regional missile defenses, though some experts have questioned whether they have consistently reached the speeds claimed by the North during tests.

KCNA's photos of Sunday's tests showed what appeared to be two missiles tipped with conical, finned vehicles being fired from launcher trucks. Kim is seen looking at a monitoring screen that identifies the missile as a Hwasong-11Ma, a system North Korea has previously described as hypersonic.

The launches were the latest in a series of weapons demonstrations by North Korea even after U.S. President Donald Trump scaled back a joint military exercise with South Korea last month in an apparent effort to revive diplomacy with Kim, who has called such drills invasion rehearsals. Kim's sister and senior official, Kim Yo Jong, dismissed Trump's overture, saying that shortening the drill would not change its "provocative, aggressive nature."

Emboldened by his advancing nuclear arsenal and deepening ties with Russia and China, experts say Kim Jong Un likely sees himself as having greater leverage in any renewed diplomacy with Trump. His government has said Washington must first drop its "hostile policy" — a term Pyongyang mainly uses to describe U.S.-led sanctions and joint U.S.-South Korea military drills — and abandon demands for North Korea's denuclearization as a precondition for talks.