SEOUL, South Korea: North Korea, on June 4, revealed a new facility for producing fuel used in nuclear weapons, with leader Kim Jong Un saying the country plans to expand its nuclear forces rapidly.

Some experts still doubt whether North Korea has fully working nuclear missiles that can reach the U.S. mainland. However, revealing this new plant suggests Kim wants to establish North Korea as a nuclear power firmly and is not willing to negotiate away its weapons program.

After visiting the facility, Kim said he and senior officials had agreed on steps to carry out a major plan to strengthen the country's nuclear forces at a very fast pace, according to state media.

North Korea's Korean Central News Agency (KCNA) said the facility uses more advanced technology but did not reveal its location. South Korea's military believes it is a uranium enrichment plant and said it is working closely with the United States to monitor North Korea's nuclear activities.

Photos released by KCNA showed Kim walking through rows of metal tubes and pipes, likely inside a centrifuge hall. Another image showed him in a meeting room with officials, looking at a blurred diagram that might depict a warhead design, though this was not confirmed.

This is the third time North Korea has shown a uranium enrichment site. In 2010, it revealed one at its Yongbyon nuclear complex to visiting U.S. experts. In 2024, it released images of another hidden facility, believed to be at Kangson.

Experts believe the newly revealed site is another enrichment facility at Yongbyon, possibly a major expansion. One expert said it appears to be a two-level structure and shows a significant increase in North Korea's ability to produce nuclear material. He added that North Korea's nuclear expansion is likely to continue without stopping anytime soon.

South Korea has previously said North Korea operates about four uranium enrichment plants, all running daily.

During his visit, Kim said the need to strengthen nuclear weapons has increased due to tensions with what he called "the most aggressive enemies," likely referring to the United States and South Korea. He repeated that North Korea's status as a nuclear weapons state will not change and claimed its production of nuclear materials has more than doubled in the past five years, though this cannot be independently verified.

Experts say Kim wants global recognition as a nuclear power so he can push for the removal of U.N. sanctions. They believe he may later seek arms reduction talks with the U.S. in exchange for giving up part of his nuclear program.

U.S. President Donald Trump has said he wants to restart talks with Kim, but North Korea has insisted that the U.S. must first drop its demand for complete denuclearization.

Since talks broke down in 2019, North Korea has carried out many weapons tests and repeatedly promised to expand its nuclear arsenal greatly.

Many experts now think North Korea likely has missiles capable of reaching the U.S., though some say it has not yet proven it can overcome key technical challenges, such as protecting warheads during reentry into the atmosphere. They also say North Korea needs to improve its ability to place multiple warheads on a single missile to get past missile defense systems.

Estimates from South Korea in 2018 suggested North Korea had between 20 and 60 nuclear weapons, but some experts now believe it may have more than 100.

In 2023, North Korea introduced a new type of smaller battlefield nuclear warhead. Some analysts thought this might lead to another nuclear test, but North Korea has not carried one out. Its last test was in September 2017, and a new one would be its seventh.