North Korea has “probably developed miniaturised nuclear devices to fit
into the warheads of its ballistic missile”, according to a confidential UN report.
It says several unidentified countries believe North Korea’s past six nuclear tests have likely helped it to develop such a capability.
An interim version of the report – by an independent panel monitoring United Nations sanctions – was submitted to the UN Security Council on Monday and has been seen by the Reuters news agency.
It also accuses North Korea of continuing its nuclear ambitions, despite it not carrying out a nuclear test for nearly three years.
The report states: “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.”
One country – not identified – believes North Korea “may seek to further develop miniaturisation in order to allow incorporation of technological improvements… or, potentially, to develop multiple warhead systems”.
The secretive communist state has been subject to UN sanctions for many years over its ballistic and nuclear missile programmes.
North Korean leader Kim Jong Un has met Donald Trump three times since 2018 in the hope that sanctions could be eased if it denuclearises, but a deal has proved elusive.
A summit in Vietnam in 2019 was cut short, with Mr Trump saying it was because his counterpart wanted all sanctions lifted – a claim denied by North Korea.
The UN report also casts doubt on the effectiveness of the destruction of tunnels at North Korea’s main nuclear site, Punggye-ri, in May 2018.
International experts were not allowed in, and the report says only tunnel entrances are known to have been destroyed rather than a complete demolition.
One country is said to have assessed that it would take only three months for North Korea to get the site capable of conducting a nuclear test again.
With North Korea’s economy still punished by sanctions, the report says it continues to break the rules and generate money through “illicit maritime exports of coal”, as well as widespread hacking.
It is estimated to have stolen $2bn (£1.7bn) through cyber attacks targeting banks and cryptocurrency exchanges.
“The Panel continues to assess that virtual asset service providers and virtual assets will continue to remain lucrative targets for the Democratic People’s Republic of Korea to generate revenue, as well as mining cryptocurrencies,” it said.