SEOUL, South Korea (AP) – In a significant show of defiance against the United States, North Korea on Friday provided the outside world with a rare view into a secretive facility built to enrich uranium for nuclear bombs as leader Kim Jong Un called for a rapid expansion of his nuclear weapons program.

Here is a look at what we know about the facility and North Korea’s capabilities for producing bomb fuel.

What Are We Seeing?

North Korea’s official Rodong Sinmum newspaper published several photos showing Mr. Kim talking with scientists and military officials in a hall tightly packed with gray centrifuge tubes that were about the height of his shoulders. The North did not specify where the facility is located or when Mr. Kim went there.

Experts say the North Korean photos likely disclosed a centrifuge room at one of its two known plants in the towns of Yongbyon and Kangson, both near Pyongyang, which had been linked to uranium enrichment activities. While North Korea is believed to have other hidden uranium sites, it was unlikely that they were showcased publicly through visits by Mr. Kim, whose activities are closely monitored and analyzed by the outside world.

Yang Uk, an analyst at South Korea’s Asan Institute for Policy Studies, said the number of centrifuges shown in the North Korean photos would be about 1,000. That happens to be roughly the number of centrifuges it would take to produce enough uranium for a single bomb—about 20 to 25 kilograms—when the devices are fully operated year-round.

It was the first time the North has disclosed a uranium enrichment facility since 2010, when it allowed a group of Stanford University scholars led by nuclear scientist Siegfried Hecker to tour its centrifuge facility in Yongbyon.

How Worried Should We Be?

As foreign experts and government officials closely securitized the reports and visuals from North Korea, it was not immediately clear whether the country was communicating something significantly new about its bomb fuel technologies.

But the news was a stark reminder of a known but growing threat, as Mr. Kim continues to speed up the expansion of his nuclear weapons and missile programs amid halted diplomacy with Washington and Seoul.

Mr. Kim in recent months has repeatedly called for an “exponential” expansion of his country’s nuclear arsenal to counter what he perceives as external U.S.-led threats. The photos released on Friday were likely intended to demonstrate that the country has the bomb fuel capacity to match the ambitions of its leader, experts say.

Mr. Kim has since 2022 been accelerating the expansion of his nuclear-capable missile systems, which include weapons designed to strike both the U.S. mainland and American allies in Asia.

North Korea’s progress in its uranium enrichment program is a major concern for rivals and neighbors. Highly enriched uranium is easier than plutonium to engineer into a weapon. And while plutonium facilities are large and produce detectable radiation, making them easier for satellites to detect, uranium centrifuges can be operated almost anywhere, including small factories, caves, underground tunnels or other hard-to-reach places.

Mr. Yang said it is estimated that North Korea could be operating around 10,000 uranium centrifuges across multiple sites, which account for the core of the country’s nuclear program that likely produces enough fuel to make around 12 to 18 bombs a year. By 2027, North Korea would possibly amass enough fuel to produce about 200 bombs, he said.

In a report this week, Rafael Grossi, director general of the International Atomic Energy Agency, said his agency has monitored continued activities at both Yongbyon and Kangson facilities.

Mr. Grossi said that at Yongbyon, IAEA had observed water outflows from the cooling water system of the light-water reactor and other indications consistent with the operation of 5-megawatt reactor and the reported centrifuge enrichment facility. The light-water reactor could be an additional source of weapons-grade plutonium along with the widely known 5-megawatt reactor, observers say.

He said that in 2024, a new annex to the main building in the Kangson complex was built, expanding the available floorspace.

Where Do We Stand on Nuclear Diplomacy?

Former U.S. President Donald Trump’s administration had an opportunity to slow the expansion of North Korea’s nuclear program while he engaged in high-stakes diplomacy with Mr. Kim starting in 2018. However, the talks broke down after their second summit in 2019, when the Americans rejected North Korean demands for major sanctions relief in exchange for the dismantling of the Yongbyon complex, which was seen as just a partial surrender of its nuclear capabilities.

Nuclear talks remain stalled as Mr. Kim vows to push his nuclear ambitions further in the face of deepening confrontations with Washington. Experts say Mr. Kim’s long-term goal is to force the United States into accepting the idea of the North as a nuclear power and negotiating economic and security concessions from a position of strength.

Some have speculated that he might try to drum up pressure in a U.S. election year, possibly with a long-range missile demonstration or a nuclear test detonation.

Mr. Kim’s visit to the nuclear facility was somewhat reminiscent of highly public visits by former Iranian President Mahmoud Ahmadinejad to the country’s Natanz uranium enrichment plant, after the country declared in 2006 that it was resuming enrichment that had been suspended for three years.

After years of difficult negotiations, Iran and six world powers led by the United States announced a comprehensive nuclear agreement in 2015 that outlined long-term restrictions on Iran’s nuclear program and the removal of many international sanctions.

However, the deal collapsed in 2018 when Mr. Trump unilaterally withdrew Washington from the agreement, calling it the “worst deal ever.” The West has struggled to find a new deal with Iran, whose advancing nuclear program now enriches uranium closer than ever to weapons-grade levels.