North Korea builds new Yongbyon uranium enrichment facility, IAEA says

North Korea has built a new uranium enrichment facility at its main Yongbyon nuclear complex that could house up to 28 centrifuge cascades and has started operating an expanded annex at its Kangson enrichment site, the International Atomic Energy Agency (IAEA) said.

The Vienna-based nuclear watchdog said in a report dated 28 August that the findings pointed to a steady expansion of North Korea's nuclear infrastructure at multiple locations.

The IAEA said it relied on satellite imagery and open-source material, including photographs published by North Korean state media, to track Pyongyang's nuclear activities. The agency has had no inspectors in North Korea since 2009.

It identified a new two-storey building at Yongbyon as the site's second uranium enrichment facility by comparing state media photographs of a June visit by North Korean leader Kim Jong Un with satellite images taken during the building's construction.

Photographs from the visit indicate that gas centrifuge cascades are installed on both the upper and lower floors of the main building, the report said, adding that the building could accommodate up to 28 of the cascades shown in the photographs.

The report also said there were indications that operations began in January at a uranium enrichment facility in Kangson, near the capital Pyongyang, within an annex that had been constructed in 2024.

The IAEA said the developments in North Korea's nuclear programme violated UN Security Council resolutions.

"The ongoing operation of enrichment facilities at Kangson and Yongbyon and the reported further expansion of the DPRK's production of weapons-grade nuclear material is a cause for serious concern," IAEA Director General Rafael Grossi said in a statement to the Board of Governors on Monday, referring to the North's official name, the Democratic People's Republic of Korea.