Doha: North Korean leader Kim Jong-un has overseen a high-thrust solid-fuel missile engine test using composite carbon fiber material, calling it a major leap in strengthening the North’s nuclear forces.

According to Qatar News Agency, the test was conducted the previous day by the Missile Administration together with a chemical materials research center, the Korean Central News Agency (KCNA) said. The test on Monday “becomes the most strategically significant achievement in the defense technology modernization work we have recently conducted,” it added.

The report came a week after Kim visited a research institute that developed the engine, where he unveiled the next-generation Hwasong-20 intercontinental ballistic missile under development, saying it will use the new engine. It was the “ninth ground jet test” and “the last one in the development process,” according to KCNA.