North Korea’s nuclear machine is getting bigger: A new uranium facility, thousands of centrifuges and missiles capable of reaching America reveal how Kim Jong Un is changing the threat

For years, North Korea's nuclear programme has been difficult to measure because much of it operates behind secrecy, restricted access and carefully controlled state propaganda. Now, satellite imagery and photographs released by Pyongyang have provided another glimpse of how that programme is growing.

At the centre of the latest concern is a new two-storey uranium-enrichment building at Yongbyon, North Korea's principal nuclear complex. The International Atomic Energy Agency (IAEA) says the facility appears capable of accommodating as many as 28 centrifuge cascades, the arrangements of centrifuges used to increase the concentration of uranium-235. The agency has described the continued development of North Korea's enrichment infrastructure as a matter of "serious concern".

The IAEA has not been able to send inspectors into North Korea since Pyongyang expelled them in 2009. Its assessment therefore relies heavily on satellite imagery, publicly available information and photographs released by North Korean state media.

What is inside North Korea's new Yongbyon building?

The building was initially identified through satellite imagery as it was being constructed. According to the IAEA, photographs released after leader Kim Jong Un visited a newly inaugurated nuclear-materials production facility in June 2026 showed an interior layout consistent with the structure observed at Yongbyon.

Analysis cited by 38 North indicates that the facility could contain roughly 4,600 centrifuges arranged in 28 cascades. The publication said experts have estimated that such an installation could potentially produce around 100 to 200 kilograms of highly enriched uranium (HEU) a year, although not all of that capacity would necessarily be devoted to weapons. Some enriched uranium could instead be used as reactor fuel.

A separate estimate cited by The Guardian, drawing on 2025 analysis by the James Martin Center for Nonproliferation Studies, put potential production at about 85kg of weapons-grade uranium annually, enough for roughly three or four additional nuclear warheads depending on the amount of material required per weapon.

The difference between these estimates reflects a fundamental problem in assessing North Korea's programme: outsiders can observe buildings and equipment, but cannot directly inspect how the facilities are being operated.

Yongbyon is only part of the picture

The expansion is not confined to Yongbyon. The IAEA has also detected activity at Kangson, a separate uranium-enrichment site near Pyongyang. Satellite imagery indicates that an annex added to the complex has begun operating, with signs of additional centrifuges being installed. Because the agency has no inspectors inside North Korea, it cannot independently determine how much enriched uranium is being produced there, or rule out weapons-grade uranium production at the site.

According to 38 North, the addition of the new Yongbyon facility would support Pyongyang's claim that its capacity to produce weapons-grade nuclear material has more than doubled compared with five years earlier. That claim was made by Kim himself during his June visit.

The IAEA has also reported indications consistent with the possible reprocessing of irradiated fuel from Yongbyon's 5-megawatt reactor, potentially providing another route for producing plutonium for nuclear weapons, according to the Arms Control Association's account of Grossi's September 2026 statement.

How many nuclear weapons does North Korea actually have?

There is no authoritative public count. The Federation of American Scientists (FAS) estimates that North Korea had produced enough fissile material by the beginning of 2026 to theoretically manufacture material for at least 90 warheads, while estimating that around 60 nuclear warheads had actually been assembled. FAS stresses that the figure is uncertain and that the arsenal is likely growing.

South Korea has offered a considerably higher estimate. Its defence minister said in August that Pyongyang could possess 80 to 120 nuclear warheads, while acknowledging that the military could not independently confirm the number. The range was based on estimates by private research organisations, according to the Guardian.

Why Washington is worried

This is where the uranium facility becomes more than a construction story. North Korea is simultaneously expanding the means of delivering nuclear weapons. A 2025 Congressional Research Service assessment said Pyongyang had developed ICBMs capable of threatening the US homeland, including the Hwasong-17, Hwasong-18 and Hwasong-19.

The Hwasong-19, tested in October 2024, was assessed by a US official as capable of carrying a nuclear payload to targets across North America. The US Defence Intelligence Agency estimated in 2025 that North Korea had 10 or fewer ICBMs, while projecting that it could possess as many as 50 by 2035.

The newer solid-fuel missiles are particularly significant because they can be prepared and launched more rapidly than older liquid-fuel systems, making them harder to detect and destroy before launch.

North Korea is also developing shorter-range and intermediate-range missiles that threaten US forces and allies in East Asia. The Congressional Research Service says these systems are being designed to improve survivability, evade missile defences and place US and allied forces at risk.

That creates a layered threat: nuclear weapons could threaten South Korea and Japan directly, while increasingly capable ICBMs are intended to give Pyongyang a potential nuclear strike capability against the US mainland.