A Swedish think tank said the number of nuclear warheads possessed by North Korea is estimated at 50 this year, up 20 from a year earlier. 

The Stockholm International Peace Research Institute(SIPRI) presented the estimate in its Yearbook 2024 released on Sunday. 

The SIPRI estimated that as of January, North Korea had assembled around 50 warheads and possessed enough fissile material to reach a total of up to 90 warheads, both significant increases over the estimates for January 2023. 

The Swedish think tank said its estimate of North Korea’s operational nuclear weapons arsenal is within the 20 to 60 range noted in the latest publicly available intelligence assessments issued by South Korea in 2018 and the U.S. in 2020. The research institute added that the number of nuclear warheads North Korea actually possesses is highly uncertain.

The SIPRI said that North Korea has been producing plutonium used in nuclear weapons, but it is also believed to be producing highly enriched uranium(HEU) for use in its nuclear warheads.