SEOUL, Jan. 11 (UPI) -- North Korea has stockpiled about 110 pounds of plutonium in its arsenal and is making steady progress in the miniaturization of nuclear weapons.
According to a 2016 white paper issued by South Korea's defense ministry on Wednesday, Pyongyang has amassed additional plutonium since 2014, when the country was estimated to have accumulated nearly 90 pounds of fissile material, South Korean newspaper Donga Ilbo reported.
The amount of plutonium North Korea currently holds is enough to make 7 to 12 nuclear weapons, with each weapon requiring 9 to 13 pounds of plutonium.
Under Kim Jong Un, the country has also been developing its highly enriched uranium program and making advancements in the miniaturization of nuclear warheads, according to the white paper. The HEU program is at a "considerable level" but more specific estimates could not be made because the program takes place in an underground facility, the report stated.
The numbers were based on South Korean military estimates of North Korea's plutonium reserves that were based on the starts and stops of the nuclear reactors in Yongbyon, reprocessing trends of spent fuel rods and plutonium usage during nuclear tests.
The South Korean defense paper stated it's unlikely North Korea has developed an intercontinental ballistic missile capable of reaching the U.S. mainland despite verbal threats, a reference to Kim's New Year speech on his readiness to launch an ICBM.
The white paper also defended Seoul's plan to remove Kim, a plan known as Korea Massive Punishment and Retaliation, because the plan counters North Korea threats, including its strategy to "decouple" United States-South Korea cooperation, local newspaper Maeil Business reported.
Kim Tae-woo, a former director at the Korea Institute for National Unification, said KMPR activation is the most urgent matter for Seoul because South Korea "must have the ability to punish North Korea" in the face of a weapons buildup.