North Korean leader Kim Jong-un has inspected a newly commissioned nuclear material production facility and pledged to ‘exponentially’ expand the country's nuclear arsenal, state media reported on 4 June. The visit, made a day earlier alongside senior party officials, was disclosed by the Korean Central News Agency (KCNA) without specifying the site's location.

Seoul flags suspected fourth enrichment site

South Korea's defence ministry, in a press briefing in Seoul, assessed the newly revealed plant as a uranium enrichment facility. North Korea is currently believed to operate enrichment sites at Yongbyon, Kangson and Kusong, and it remains unclear whether the latest disclosure points to a fourth location.

Photos released by KCNA showed rows of cylindrical centrifuges used for uranium enrichment inside the facility. A separate image showed Kim seated at a table with documents — reportedly tied to Pyongyang's nuclear weapons programme — blurred from view.

What Kim said

Kim claimed the country's ‘weapons-grade nuclear material production capacity more than doubled’ over the past five years, crediting North Korean nuclear scientists, according to the report. ‘Potential threats and unpredictable long-term crises further highlight the urgency’ of expanding the nuclear deterrent ‘both in quality and quantity and in a sustained and accelerated way,’ he said, signalling no rollback of Pyongyang's nuclear ambitions.

State media also reported an ‘important consultative meeting for bolstering up the nuclear forces’ held on the same day, where Kim issued ‘action guidelines for rapidly accelerating the qualitative and quantitative’ buildup. ‘Today we have updated the digits that are critical for our nuclear activities,’ he said, adding that Pyongyang had ‘confirmed the order of priority’ for a plan to ‘beef up our state's nuclear forces at an exponential rate.’ He described it as a ‘historic event that has set up an epochal milestone in rapidly upgrading our nuclear capabilities.’

Background: an ‘irreversible’ nuclear state

At a key party congress in February, Pyongyang reaffirmed its status as an ‘irreversible’ nuclear-armed state and pledged to further strengthen its deterrent under a five-year military modernisation plan. In September 2024, North Korea publicly disclosed a uranium enrichment facility for the first time and called for an increase in the number of centrifuges.

Unification Minister Chung Dong-yong said at that time that North Korea was operating four nuclear enrichment sites and was estimated to possess up to 2,000 kg of highly enriched uranium at 90% purity or higher. Roughly 10 to 12 kg of such uranium is sufficient to produce one nuclear bomb, he added.

Third such inspection in under a year

According to a unification ministry official, the latest KCNA report marks the third disclosed visit by Kim to a nuclear facility, following inspections in September 2024 and January 2025. The pattern suggests a deliberate strategy of public signalling, timed to underscore Pyongyang's defiance of international sanctions.

What happens next

Analysts will be watching for satellite imagery that could help locate the new site and confirm whether it constitutes a fourth enrichment hub. The disclosure is likely to renew pressure on Seoul, Washington and Tokyo to recalibrate their deterrence posture as Pyongyang accelerates its fissile material production.