SEOUL — North Korean leader Kim Jong Un observed a test of a high-thrust solid-fuel engine for weapons as part of the country's five-year military escalation program. The tested engine produced a maximum thrust of 2,500 kilotons and used composite carbon fiber material.

The engine test represents an increase in thrust capability compared to a similar solid-fuel engine tested in September, which had a maximum thrust of about 1,971 kilotons. The test forms part of North Korea's five-year military escalation program, which aims to upgrade strategic strike means.

"The engine test was highly significant for North Korea's strategic military capabilities," Kim said, according to official statements. He said the test would "boost North Korea's strategic military capability."

North Korea has previously test-fired intercontinental ballistic missiles with a potential range to reach the U.S. mainland. Some of these tested missiles used solid propellants that make detection prior to liftoff more difficult, unlike older liquid-fuel missiles that require fueling before liftoff and cannot be stored fueled for extended periods.

Missiles capable of reaching the U.S. mainland are nuclear-capable intercontinental ballistic missiles. Since 2019, North Korea has pushed to expand its nuclear arsenal.

In a speech at North Korea's Parliament, Kim pledged to irreversibly cement North Korea's status as a nuclear power and accused the U.S. of global state terrorism and aggression. At the Workers' Party congress in February, Kim said he remained open to dialogue with Donald Trump while urging Washington to drop nuclear disarmament demands as a precondition for talks.