Jakarta, CNBC Indonesia – North Korea’s (North Korea) nuclear arsenal is estimated to be much larger and growing faster than global assumptions. The latest assessment by South Korean (South Korean) defense researchers suggests that Pyongyang may already have up to 150 nuclear warheads, twice as many as international agencies estimate.
In a forum held by the Korean Institute for Defense Analysis (KIDA), Head of KIDA’s Nuclear Security Research Division, Lee Sang-kyu, stated that North Korea may have 127 to 150 nuclear weapons. This is based on recent levels of fissile material production and facility expansion.
“North Korea has expanded and modernized its sites to increase its nuclear material production capabilities,” Lee was quoted as saying Korea HeraldThursday (27/11/2025).
Lee stressed that North Korean leader Kim Jong-un‘s order to increase warhead production “exponentially” continued to fuel rapid growth. Lee estimates North Korea’s nuclear arsenal could reach 200 units by 2030 and exceed 400 units by 2040 if expansion of uranium enrichment facilities and plutonium production continues.
Its internal analysis suggests Pyongyang may have 115-131 uranium-based and 15-19 plutonium-based warheads. This is far above the estimates of international institutions such as the Congressional Research Service (CSR), which still predicts around 50 units.
KIDA researchers assess this acceleration is partly driven by the expansion of uranium enrichment infrastructure. An IAEA report in August identified new buildings at Yongbyon that were suspected of expanding enrichment capacity.
Lee also highlighted North Korea’s nuclear-powered submarine project announced this year. However, it is considered still far from mature.
“Developing a compact nuclear reactor with a high enrichment rate will take at least a decade,” he said.
However, he warned the process could be faster if Russia provided technological support, including design and critical materials. Even though Pyongyang is increasingly vocal about claiming a second nuclear strike capability against the US, KIDA analysts warn that North Korea’s operational readiness is not yet solid.
“Outwardly, North Korea has built up the appearance of such capabilities. However, substantial improvements are still needed for true military effectiveness,” said KIDA researcher Jeon Gyeong-ju.
Satellite imagery monitoring by the AS 38 North site also shows a continued increase in nuclear activity throughout 2025. Modernization and expansion are visible at the Yongbyon Nuclear Scientific Research Center, including the replacement of enrichment at the most active point.
The group noted the stable operation of the 5 megawatt reactor as well as initial tests of an experimental light water reactor, which “reflects Kim Jong-un’s directive to accelerate the production of weapons-grade materials.”
“All of these improvements are aimed at fulfilling Kim’s call to increase his nuclear arsenal exponentially,” wrote the 38 North report.
(boss/boss)
[Gambas:Video CNBC]