Pyongyang is under multiple sets of international sanctions over its nuclear and ballistic missile programmes, which have seen rapid progress under current leader Kim Jong Un.

The report's publication comes after Pyongyang sparked international concern with a series of missile tests in the span of a few weeks, prompting the UN Security Council to hold an emergency meeting.

The report -- which was published online Tuesday Seoul time, and covers the period from February 6 to August 3 -- said the North continued to polish its weapons programmes.

"Despite the country's focus on its worsening economic travails, the Democratic People's Republic of Korea continued to maintain and develop its nuclear and ballistic missile programs," said the report, compiled by a panel of experts monitoring sanctions on the isolated country.

The Democratic People's Republic of Korea is the official name of the North, which like the South last month saw the 30th anniversary of their simultaneous admission to the United Nations.

Pyongyang has not carried out an intercontinental ballistic missile launch or nuclear test since 2017 but the report said tests "combining ballistic and guidance technologies" were conducted while activity continued at key sites related to the nuclear programme.

In early 2020 the country closed its borders to try to protect itself against the coronavirus pandemic, which first emerged in neighbouring China, but has nonetheless "continued its illicit efforts to procure specific components from overseas and to seek opportunities to transfer its own products to its partners", the report added.

It said the North's coronavirus blockade had continued "fundamentally to impact the movement of people and goods, both licit and illicit, within, into and out of the country".

The import of consumer products, including luxury goods banned under UN sanctions, had "virtually stopped", the report said, but said it was investigating illicit transfers of luxury vehicles.

Leader Kim has been seen using Lexus SUVs in recent months and the report highlighted an attempted shipment of more than $1 million-worth of luxury vehicles, including such models, allegedly from the United Arab Emirates to Ningbo, China, for onward delivery to the North.

Pyongyang has stayed away from nuclear talks since the collapse of a second summit between Kim and then US president Donald Trump in Hanoi and has rebuffed South Korean efforts to revive dialogue.

Under President Joe Biden, the United States has repeatedly declared its willingness to meet North Korean representatives, while saying it will seek denuclearisation.

Last week, Kim decried Washington's repeated offers of talks without preconditions as a "petty trick", accusing the Biden administration of continuing the "hostile policy" of its predecessors.