North Korea's Korean Central News Agency (KCNA) reported on March 29 that North Korean leader Kim Jong-un observed a ground ejection test of a high-thrust solid-fuel engine using carbon fiber composite materials. The announcement came amid the escalating war between the U.S./Israel and Iran, as Pyongyang unveiled the development of a new engine for an intercontinental ballistic missile (ICBM) capable of striking the U.S. mainland.
According to KCNA, the newly upgraded engine's maximum thrust is 2,500 kN (kilonewtons). This represents a roughly 26% increase from the 1,971 kN maximum thrust of the solid-fuel engine tested in a ground ejection test in September last year. The engine is likely to be installed on the Hwasong-20, a new multiple independently targetable reentry vehicle (MIRV)-capable ICBM unveiled at the military parade celebrating the 80th anniversary of the founding of the Workers' Party of Korea.
As engine thrust increases, an ICBM's range grows proportionally. North Korea has already developed ICBMs with a range of approximately 15,000 km, putting most of the U.S. mainland within striking distance. Its pursuit of more powerful solid-fuel engines signals an effort to advance its multi-warhead ICBM capabilities. Experts assessed that Pyongyang was sending a message to Washington: "North Korea is different from Iran and Venezuela — don't provoke us."
Why is North Korea pouring all its resources into developing new solid-fuel ICBMs? Solid-fuel ICBM development is one of the five key objectives in the "Five-Year Plan for National Defense Science Development and Weapons Systems Development" that Kim Jong-un presented in January 2021. From a military standpoint, solid-fuel ICBMs are classified as the strategic assets most feared by adversaries, making them the weapon system Kim wants most.
Solid-fuel ICBMs require no fueling before launch, enabling firing within minutes. They are easily concealed and capable of surprise attacks using transporter erector launchers (TELs), making detection and interception difficult. In contrast, liquid-fuel ICBMs require lengthy fueling times, extending launch preparation and increasing the risk of detection and interception during the process.
