March 27, 2017 0425 GMT
In its 2016 defense white paper, the South Korean Ministry of National Defense estimated that North Korea had developed the aforementioned amount of plutonium as of the end of 2016.
According to the report, the North had a stockpile of plutonium at about 40 kilograms in 2014.
The ministry also claimed that Pyongyang had a “considerable” ability to produce weapons based on highly-enriched uranium. It did not provide more details.
North Korean leader Kim Jong-un said in a New Year address that his country was in the “final stages” of developing an intercontinental ballistic missile — capable of reaching US mainland.
Earlier on Sunday, US Defense Secretary Ashton Carter called North Korea a “serious threat” and warned that Washington would shoot down any missile aimed at the US or any of its allies.
China and South Korea also denounced Pyongyang’s missile program on Monday and warned to impose more sanctions on the country if it attempted to test launch more missiles.
North Korea, long under strict international sanctions, has so far refused to stop developing its missile and nuclear program, asserting that the tests aim to protect the country from the hostile US posture. The US has military forces in South Korea and is planning to controversially deploy an advanced missile system in the country as well. It also occasionally deploys nuclear-powered warships and aircraft capable of carrying atomic weapons in the region.
North Korea’s fifth and biggest nuclear test on September 9 last year prompted the United Nations Security Council to impose a fresh round of sanctions against Pyongyang.