A new assessment by the Korea Institute for Defense Analyses (KIDA) warns that North Korea’s nuclear weapons program may be far larger — and expanding far faster — than commonly understood.
According to The Korea Herald, Lee Sang-kyu, head of KIDA’s nuclear security division, told a forum this week that Pyongyang likely possesses between 127 and 150 nuclear weapons, more than double the figures cited by most international organisations, which tend to estimate around 50 warheads. Lee said KIDA’s higher estimate stems from a detailed review of North Korea’s nuclear material production and recent facility expansions.
Lee projected that North Korea’s arsenal could rise to 200 nuclear weapons by 2030 and surpass 400 by 2040 if current trends continue. He cited Kim Jong-un’s directive for an “exponential” increase in warhead production, which has led the regime to scale up both uranium enrichment and plutonium production.
Breaking down the estimates, Lee said Pyongyang may already hold 115–131 uranium-based warheads and 15–19 plutonium-based weapons, underscoring the size of a stockpile that “many outside experts continue to underestimate.”
KIDA analysts attribute the rapid growth partly to the construction of new enrichment facilities. The International Atomic Energy Agency recently reported a newly identified building at the Yongbyon complex that appears intended for uranium enrichment. Meanwhile, satellite imagery examined by the U.S. monitoring group 38 North shows continued upgrades at Yongbyon in 2025, including support structures and equipment linked to centrifuge operations.
Lee also addressed North Korea’s nuclear-powered submarine project, showcased publicly for the first time this year. He said the vessel remains incomplete, with crucial components — including its reactor and sonar systems — still missing. North Korea could take a decade to develop a functional submarine reactor “unless Russia accelerates the timeline,” he warned, noting deepening Pyongyang–Moscow military cooperation since their 2023 summit. This has heightened concerns about possible nuclear-related technology transfers.
Despite North Korea’s aggressive rhetoric about its ability to deter or strike back against the United States, KIDA experts advised caution in interpreting Pyongyang’s capabilities. Researcher Jeon Gyeong-ju said the North is attempting to project readiness for a limited nuclear conflict, but its systems are not fully mature.
“Outwardly, North Korea has assembled the appearance of such a capability,” Jeon said. “But real effectiveness still requires more development.”
The study’s findings add to growing unease in Seoul, Washington and Tokyo over North Korea’s rapidly evolving nuclear posture, even as the regime continues to defy sanctions and accelerate weapons development.
