North Korea building up nuclear arsenal, researchers say

June 9 (UPI) -- North Korea may have as many as 35 nuclear warheads in its arsenal, up from a previous estimate, according to a Japanese think tank.

The Research Center for Nuclear Weapons Abolition, RECNA, at Nagasaki University says North Korea's weapons are included in a global total of 13,410 nuclear weapons, Japanese news agency Kyodo News reported Tuesday.

North Korea's warheads lag far behind other countries. Russia is No. 1 on RECNA's list, with 6,370 nuclear warheads, followed by the United States at 5,800 and China at 320, according to the report.

Other countries keep more than 100 nuclear warheads. According to RECNA's estimates, France retains 290 warheads, followed by Britain at 195, Pakistan at 160, and India at 150. Israel has developed about 80 to 90 nuclear weapons.

The number of nuclear weapons worldwide is down, RECNA says, with 470 less weapons than a year ago.

North Korea has increased its nuclear arsenal, however, according to the estimates. In 2019, RECNA calculated about 20 to 30 nuclear weapons for the isolated country.

China has also added about 30 nuclear weapons since 2019, a year of high tensions with the United States, RECNA said.

Top U.S. weapons expert Siegfried Hecker has previously said North Korea would never give a full declaration of its nuclear weapons.

"A complete account of North Korea's nuclear weapons, materials and facilities would, in Kim [Jong Un's] view, likely be far too risky in that it would essentially provide a targeting list for U.S. military planners and seal the inevitable end of the nuclear program and possibly his regime," Hecker wrote in 2018.

The North Korean leader has previously proposed dismantling the Yongbyon nuclear complex if the United States takes reciprocal measures -- namely sanctions relief.

Recent satellite imagery analysis by U.S. analyst Jacob Bogle indicates North Korea could be maintaining underground facilities near Yongbyon, in an adjacent workers' district.