1225 GMT September 20, 2020
The report by an independent panel of experts monitoring UN sanctions said the countries, which it did not identify, believed North Korea's past six nuclear tests had likely helped it develop miniaturized nuclear devices. Pyongyang has not conducted a nuclear test since September 2017.
The interim report, seen by Reuters, was submitted to the 15-member UN Security Council North Korea sanctions committee on Monday.
"The Democratic People's Republic of Korea is continuing its nuclear program, including the production of highly-enriched uranium and construction of an experimental light water reactor. A member state assessed that the Democratic People's Republic of Korea is continuing production of nuclear weapons," the report said.
North Korean leader Kim Jong-un said last week there would be no more war as the country's nuclear weapons guarantee its safety and future despite unabated outside pressure and military threats.
The UN report said one country assessed that North Korea "may seek to further develop miniaturization in order to allow incorporation of technological improvements such as penetration aid packages or, potentially, to develop multiple warhead systems."
North Korea has been subjected to UN sanctions since 2006 over its nuclear and ballistic missile programs. While the Security Council has steadily strengthened sanctions in a bid to cut off funding for those programs.
Kim and US President Donald Trump have met three times since 2018, but failed to make progress on North Korea's demands for an end to sanctions and US calls for Pyongyang to give up its nuclear weapons.
Early this year, Kim called off two years of the moratorium on nuclear and missile tests and said Pyongyang would soon develop a “new strategic weapon.”
He said last week that his county now had “absolute might” thanks to its nuclear weapons, which he said guaranteed its security in the face of threats of war.
In May 2018, North Korea followed through on a pledge to blow up tunnels at its main nuclear test site, Punggye-ri, which Pyongyang said was proof of its commitment to end nuclear testing.
The UN report said that as only tunnel entrances were known to have been destroyed and there is no indication of a comprehensive demolition, one country had assessed that North Korea could rebuild and reinstall within three months the infrastructure needed to support a nuclear test.