In a 62-page report sent to the Security Council, the UN panel of experts also listed violations of a ban on North Korean exports of coal, iron, seafood and other products that generate millions of dollars in revenue to Kim Jong Un's regime.

The transfer of petroleum products to North Korean tankers at sea remains "a primary method of sanctions evasion" involving 40 vessels and 130 associated companies, said the report seen by AFP.

North Korea "has not stopped its nuclear and missile programs and continued to defy Security Council resolutions through a massive increase in illicit ship-to-ship transfers of petroleum products, as well as through transfers of coal at sea during 2018," said the report sent to the council.

The violations have rendered the latest batch of sanctions "ineffective" by flouting the cap on oil, fuel and coal imposed in a raft of UN resolutions adopted last year, it added.

- Arms peddling through Syria -

North Korea also "attempted to supply small arms and light weapons (SALW) and other military equipment via foreign intermediaries" to Libya, Yemen and Sudan, said the report.

It named Syrian arms trafficker Hussein Al-Ali who offered "a range of conventional arms, and in some cases ballistic missiles to armed groups in Yemen and Libya" that were produced in North Korea.

With Ali acting as a go-between, a "protocol of cooperation" between Yemen's Huthi rebels and North Korea was negotiated in 2016 in Damascus that provided for a "vast array of military equipment."

The panel continues to investigate the military cooperation that would be in violation of an arms embargo on North Korea.

North Korea continued to receive revenue from exports of banned commodities, for instance deliveries of iron and steel to China, India and other countries that generated nearly $14 million from October to March.

"Financial sanctions remain some of the most poorly implemented and actively evaded measures of the sanctions regime," said the panel.

North Korean diplomats play a key role in sanctions evasion by setting up multiple bank accounts, it added.

Despite a ban on joint ventures with North Korea, the panel has uncovered more than 200 such jointly-run firms, many of which are involved in construction and other businesses in Russia.

The panel is tasked by the council with monitoring the implementation of the raft of sanctions imposed in response to North Korea's sixth nuclear test and ballistic missile tests.

The United States last month asked a UN sanctions committee to order a halt to all deliveries of oil products to North Korea after reporting that Pyongyang had exceeded the cap on fuel supplies through the illegal ship supplies.

Russia and China however put a six-month hold on that request.

The report cited US figures estimating that North Korea had procured over 500,000 barrels of petroleum products in the first five months of 2018, meaning that it would now be in violation of sanctions resolutions.