A confidential UN report submitted Monday says North Korea is pressing on with its nuclear weapons program, ignoring sanctions.
And -- it says several unidentified countries believe Pyongyang has likely developed nuclear devices to fit ballistic missiles.
The interim report, which was viewed by Reuters believes North Korea's past six nuclear tests gave it a leg up on making smaller nuclear devices.
Those are believed to fit into its ballistic missile warheads.
North Korea's mission to the United Nations did not immediately respond to a request for comment on the report.
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 what he called ongoing outside pressure and military threats.
North Korea has been under U.N. sanctions since 2006 over its nuclear and ballistic missile programs.
The UN has steadily ratcheted up sanctions in a bid to cut off funding for those programs.
Pyongyang has not conducted a nuclear test since September 2017, before Kim Jong Un and U.S. President Donald Trump sat for talks in Singapore the following year.
Also in 2018, North Korea blew up the tunnels at its main nuclear test site, Punggye-ri.
Pyongyang said this was proof of its commitment to end nuclear testing.
But they did not allow experts to witness the site being dismantled.
The U.N. report said that since there is no indication of a comprehensive demolition, one unnamed country had assessed that North Korea could rebuild and reinstall the infrastructure needed to support a nuclear test -- within three months.
The U.N. experts also say North Korea is violating sanctions through quote "illicit maritime exports of coal," though this was temporarily suspended due to the global health crisis.
North Korean leader Kim Jong Un and U.S. President Donald Trump have met three times since 2018.
But they have failed to make progress on U.S. calls for Pyongyang to give up its nuclear weapons -- and North Korea's demands for an end to sanctions.