North Korea conducts engine test for missile capable of reaching U.S. mainland

Key Points:

• North Korean leader Kim Jong Un observed a test of an upgraded solid-fuel missile engine, which state media described as a significant advancement enhancing the country's strategic military capabilities.
• The tested engine reportedly has a maximum thrust of 2,500 kilonewtons, an increase from a previous test in September, and uses composite carbon fiber materials; however, some experts question the completeness and accuracy of North Korea's claims.
• Solid-fuel engines offer advantages such as easier mobility and quicker launches compared to liquid-fuel engines, potentially enabling North Korea to develop smaller, more agile intercontinental ballistic missiles (ICBMs) deployable from submarines or mobile launchers.
• Despite North Korea's claims of progress, outside analysts note unresolved technological challenges, including warhead survivability during atmospheric reentry, and suggest the country may be seeking Russian assistance to improve its missile technology.
• North Korea continues to expand its nuclear arsenal amid stalled diplomacy with the U.S., with Kim Jong Un advocating for dialogue without preconditions on denuclearization following the breakdown of talks after 2019.