Photo taken July 14, 2020, from Paju, a South Korean city just south of the truce village of Panmunjeom, shows a North Korean flag.
United Nations CNN  — 

North Korea is continuing work on its nuclear program and several countries believe Pyongyang has made gains in producing ballistic missiles with small nuclear devices attached, according to a confidential United Nations (UN) report, a UN diplomat told CNN.

The latest report was prepared by a UN-appointed independent panel of experts, who are charged with monitoring sanctions enforcement and efficacy. It says the unnamed countries believe North Korea “probably developed miniaturized nuclear devices to fit into the warheads of its ballistic missiles.”

The experts, who do not have access to North Korea, rely on UN countries to supply intelligence information.

The report, which concludes that North Korea remains in violation of UN sanctions, has been circulated to the 15-nation Security Council. UN diplomats, who spoke on condition of anonymity, provided different segments of the report to CNN.

The report says “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 DRPK is continuing production of nuclear weapons.”

The independent experts reported that one country, which wasn’t named, claimed 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.”

In addition, North Korea had vowed it destroyed or dismantled tunnels into a main nuclear site in May 2018. The report concludes that only tunnel entrances were known to have been destroyed and there is no indication of a comprehensive demolition.

One country also assessed that North Korea could rebuild and reinstall within three months the infrastructure needed to support a nuclear test, the report said.

There hasn’t been a known nuclear test inside North Korea since September 2017. The regime frequently praises its nuclear weapons as a block against outside aggression. On July 27, Kim Jong-Un said there will be no more war because the country has a nuclear deterrent.

The report also noted that North Korea had not stopped violations highlighted in previous reports.

A UN report last year concluded North Korea generated around $2 billion using cyberattacks to plunder banks and cryptocurrency exchanges. The summary of that report indicated North Korea is probing Security Council countries in cyberattacks.

Though not responding directly to the 2020 report, US Ambassador to the UN Kelly Craft told a gathering at the Aspen Institute on Tuesday that US policy toward Pyongyang hasn’t changed and that the US still seeks denuclearization in the region.

“It is something that we keep a very close eye on,” she said.