North Korea Tests Upgraded Solid-Fuel Missile Engine

North Korean leader Kim Jong Un oversaw a ground test of an upgraded solid-fuel engine for intermediate- and long-range missiles on Saturday, state media reported, describing the development as a major advancement in the country's nuclear-capable arsenal.

The Korean Central News Agency announced the test Sunday, stating that Kim personally witnessed the demonstration at an undisclosed site. The engine, constructed with composite carbon fiber materials, achieved a maximum thrust of 2,500 kilonewtons, an increase from the approximately 1,970 kilonewtons recorded in a similar September trial. Officials said the engine is intended for "strategic strike means," a phrase referring to ballistic missiles that could deliver nuclear warheads. Kim described the outcome as holding "great significance in putting the country's strategic military muscle on the highest level," according to the agency.

The test aligns with North Korea's five-year military modernization plan, adopted in 2021, which emphasizes expanding its arsenal of missiles capable of reaching the United States and its allies. Solid-fuel engines offer key advantages over traditional liquid-fuel systems: they require no...