North Korea has added a new two-storey uranium enrichment facility to its nuclear portfolio, and the world's nuclear watchdog is, predictably, not thrilled. Rafael Grossi, head of the International Atomic Energy Agency (IAEA), called the development a cause for "serious concern," which is diplomatic-speak for 'we're really quite worried.'

The new building, part of the main Yongbyon nuclear complex, is reportedly capable of housing up to 28 centrifuge cascades for uranium enrichment. Because when you're already violating UN resolutions, why not go big? In a report published late last month, the IAEA also noted that Pyongyang has begun operating an expanded annex at another enrichment site, because one illicit facility is so last decade.

These findings point to a steady expansion of North Korea's sanctioned (read: illegal) nuclear infrastructure. The IAEA, which has been persona non grata in North Korea since 2009, relies on satellite imagery to keep tabs on things. It's like spying on your neighbor through their window because they kicked you out of their house - except the neighbor is building nuclear weapons.

"The continuation and further development of the DPRK's nuclear programme are clear violations of relevant UN Security Council resolutions and are deeply regrettable," Grossi said, adding a hearty 'tsk, tsk' in spirit. The IAEA first flagged the building in June, although Grossi had hinted at it earlier in the year. In June, they also noted that Kim Jong Un visited a "newly inaugurated nuclear materials production factory" on 3 June, which they identified as the Yongbyon enrichment facility. Kim praised the country's "greatly expanded production capacity," which would "offer the possibility of carrying out larger plans." Because when you're building bombs, bigger is always better.

All this nuclear ambition comes at a cost - $640 million a year, according to a 2022 report by a non-proliferation think-tank. That's a hefty price tag for a country that ranks among the world's poorest, but hey, who needs food when you can have enriched uranium? Edward Howell, a lecturer at the University of Oxford, told the BBC what makes the program so concerning: "Many of its facilities are unknown, concealed, and thus difficult to target." Beyond Yongbyon, there's Kangson, and likely more hidden sites. It's like a game of nuclear whack-a-mole, but the moles are armed with ICBMs.

The IAEA also reported indications that operations had started at another enrichment facility in Kangson, near Pyongyang, in January this year. An annex was first constructed there in 2024. In April, the agency noted that North Korea appeared to be stepping up its ability to make nuclear bombs, monitoring the apparent expansion of Yongbyon. The program has accelerated under Kim, who has overseen a record number of missile tests, including numerous intercontinental ballistic missiles (ICBMs) since 2017. North Korea has conducted six nuclear weapons tests so far, the last in September 2017.

In August, South Korea's president, Lee Jae Myung, proposed talks with North Korea on officially ending the war between the two countries, suggesting it could serve as a forum for discussing "effective ways to halt the advancement of the North's nuclear capabilities." North Korea has yet to respond, probably because they're busy building more centrifuges.

North Korea declared itself a nuclear power in 2022 and vowed never to relinquish its weapons, of which it is estimated to possess dozens. Lee previously said Pyongyang was producing 15 to 20 more warheads annually, and told the BBC last year he would back a deal between US President Donald Trump and Kim to freeze production. But until then, the world watches from space, because that's the only safe distance.