PYONGYANG—Hailing it as a significant step forward for their ballistic weapons program just hours after suffering a failed missile launch, North Korean leaders announced Monday they had successfully detonated a nuclear scientist. “It was with great satisfaction this morning that I witnessed the detonation of a 156-pound nuclear scientist,” Supreme Leader Kim Jong-un said in a recorded statement, which appears to corroborate U.S. intelligence reports that a 0.7-magnitude tremor and large explosion had been detected at a bunker outside the city of Kusong at 9:42 a.m. local time, marking the nation’s first detonation of a major scientist since the days following a catastrophic rocket malfunction in 2012. “With this glorious achievement, our laboratories have begun to move much faster toward completing our goal of building an indomitable nuclear arsenal capable of annihilating all cowardly Western aggressors. We are prepared to detonate multiple scientists every month as a demonstration of our might and determination.” Intelligence analysts have reportedly warned top American officials to take Kim at his word, noting that the North Korean regime has already built up a stockpile of nuclear scientists’ family members it is prepared to detonate at a moment’s notice.