North Korea Proclaims Final Ground Test of Carbon-Fiber Solid-Fuel ICBM Engine, Paving Way for Hwasong-20

SEOUL , September 8, 2025 : North Korea declared it has successfully carried out the final ground test of a solid-fuel rocket engine designed for a new generation of intercontinental ballistic missiles (ICBMs). The powerful engine, built with carbon-fiber materials, reportedly generates 1,971 kilonewtons of thrust, making it far stronger than earlier versions.

According to state media, the test was personally observed by leader Kim Jong Un, who hailed the breakthrough as an “eye-opening” development and a “significant change” in the country’s effort to expand its strategic nuclear forces. The new engine is set to power the Hwasong-20 ICBM, a system that North Korea recently revealed as part of its long-range missile program.

Solid Fuel and Strategic Edge

Solid-fuel technology provides crucial advantages: missiles can be launched more quickly, are easier to conceal, and are more mobile compared to older liquid-fuel systems. Analysts believe North Korea could soon move to test-firing a full ICBM equipped with this engine, possibly by the end of the year. Such a display would align with preparations for the ruling Workers’ Party Congress in early 2026, where Kim is expected to announce new policy directions.

Kim has also pushed for multi-warhead technology (MIRVs) and the miniaturization of long-range missiles, which could be deployed from mobile launchers or submarines, enhancing survivability against missile defense systems.

Remaining Technical Hurdles

Despite the advances, all North Korean ICBM launches so far have been conducted at lofted trajectories, avoiding overflight of neighboring countries. Experts note that Pyongyang may not yet have perfected the technology needed for warhead re-entry, a critical step for operational capability.

Political and Global Context

The timing of the test highlights Kim’s dual strategy: strengthening his hand in future negotiations with the United States while reinforcing ties with Russia and China. North Korea has already supplied troops and military equipment to Russia in its war in Ukraine, and Kim recently appeared alongside Vladimir Putin and Xi Jinping at a massive parade in Beijing, marking the 80th anniversary of the end of World War II.

On the same day as the engine test, China’s President Xi sent a congratulatory letter to Kim for North Korea’s founding anniversary, calling for enhanced “strategic communication” between the two allies.

Outlook

If North Korea follows through with an ICBM launch in the coming months, the test could mark its most powerful display of military capability yet, directly aimed at showcasing a missile system capable of threatening the U.S. mainland. With the Hwasong-20 nearing deployment, the balance of power and security in East Asia is likely to face renewed strain.