North Korea has conducted a test of a rocket engine, reportedly intended for use in an intercontinental ballistic missile (ICBM). The test is seen as a significant development in the country's missile program, with some outlets suggesting it could be a step towards a multi-warhead delivery system or a solid-fuel engine for long-range missiles. The implications of the test are still unclear, but it is believed to bring North Korea closer to developing a missile capable of reaching the US mainland.