North Korean Leader Kim Jong Un Gives Major Nuclear Update

North Korean leader Kim Jong Un has overseen a successful test of a high-thrust solid-fuel missile engine using composite carbon fiber material for its long-range ballistic missiles, marking a “significant” strengthening of nuclear strategic forces, state media reported.

Why It Matters

Despite U.N. sanctions, North Korea has developed increasingly sophisticated intermediate-range and intercontinental ballistic missiles (ICBMs), including systems it says can deliver nuclear warheads.

The program has heightened tensions with South Korea and has driven the U.S. and, increasingly, Japan to deepen security cooperation. North Korea says it needs to develop its weapons to defend itself from the U.S. and its Asian allies, which North Korea says are intent on attacking it.

President Donald Trump has raised the possibility of reengaging with Kim. Trump met Kim three times during the U.S. president’s first term, in an unsuccessful bid to press North Korea to give up its nuclear program in exchange for sanctions relief.

The engine test took place days after Kim paid a high-profile visit to China where he attended a military parade marking the end of World War II and met leader Xi Jinping and Russia’s President Vladimir Putin, cementing his prominent role in a bloc of countries opposed to what they see as illegitimate U.S. domination of the international order.

North Korean leader Kim Jong Un, right, watches a test of a new rocket engine at an undisclosed location, North Korea, Monday, Sept. 8, 2025, in a photo provided by the North Korean government.

Korean Central News Agency/AP

What To Know

North Korea has conducted six underground nuclear tests since 2006, the most recent in 2017. It has also tested various ICBMs, some fueled by solid-propellant and believed to be capable of reaching the U.S. mainland.

North Korean state media said the Missile Administration “conducted a ground test of a high-thrust solid-fuel engine using composite carbon fiber material” on Monday.

Kim Jong Un observed the “eye-opening” test and appreciated that the successful “development of high-thrust carbon fiber solid-fuel engine…heralds a significant change in expanding and strengthening the nuclear strategic forces of the DPRK,” state media reported, referring to North Korea by the initials of its official name, the Democratic People’s Republic of Korea.

Solid-fuel missile engines allow for much quicker responses in times of crisis because they do not need to be fueled immediately before a launch, meaning they can be easier to move and conceal. Their propellants are a mixture of fuel and oxidizer, with metallic powders such as aluminum often serving as the fuel.

North Korea uses solid fuel in a range of small, shorter-range ballistic missiles, as well as in its new Hwasong-18 intercontinental ballistic missile.

Monday’s test was the ninth of the engine built with carbon fiber and capable of producing 1,971 kilonewtons of thrust, more powerful than past models, according to the North’s official Korean Central News Agency.

The test came a week after Kim visited the research institute that developed the engine, which North Korea said will be used for future intercontinental ballistic missiles, including a system called Hwasong-20.

What People Are Saying

An official at South Korea’s Unification Ministry, which oversees dealings with North Korea, told the Yonhap news agency: “Given that it was reported right after (Kim’s) attendance at the Chinese military parade, the latest test appears aimed at the outside world, possibly a message toward the U.S.”