Many diplomats and analysts credit the sanctions, which have sharply cut North Korea's exports and imports, with helping promote the thaw in relations between North Korea and South Korea as well as the June meeting between President Donald Trump and North Korean leader Kim Jong Un.
But the report said North Korea "has not stopped its nuclear and missiles programs" and continues to defy the sanctions resolutions.
The experts said ship-to-ship transfers of petroleum products, oil and coal involve "increasingly sophisticated evasion techniques."
These include turning off Automatic Identification Systems, which are required to be on at all times under international regulations, physically disguising North Korean tankers, using small unregistered vessels, illegally changing names, carrying out night transfers and using additional vessels to trans-ship cargo, the report said.
The United States said last month that North Korea is illegally smuggling refined petroleum products into the country beyond the quota of 500,000 barrels per year allowed under UN sanctions.
US documents sent to the Security Council committee monitoring sanctions against North Korea cite 89 instances between Jan. 1 and May 30, in which North Korean tankers likely delivered refined products "illicitly procured" via ship-to-ship transfers.
The documents say that even if each tanker delivered only one-third of its listed capacity, the total volume would be above the 500,000 barrel annual quota. If loaded at around 90 percent, the US said the tankers would have delivered nearly 1.4 million barrels of refined products to North Korea, almost triple the quota.
The experts said if the report is accurate, North Korea is violating sanctions and all countries "would have to immediately halt all such transfers" to North Korea.
As for UN financial sanctions, the report said they are among the most poorly implemented and evaded measures.
The experts said individuals empowered to act for North Korean financial institutions operate in at least five countries, which weren't named, "with seeming impunity".
They said accounts closed in the European Union to comply with sanctions were transferred to accounts at financial institutions in Asia.
North Korea is also using overseas companies and individuals to obscure income-generating activities for the government, the panel said. And the experts' investigation of more than 200 joint ventures and/or cooperatives turned up a number that violated UN sanctions resolutions by maintaining links with companies and entities under sanctions.
The experts said North Korean diplomats also continue to play "a key role in sanctions evasion," including by controlling bank accounts in multiple countries and holding accounts in the name of family members and front companies.
- AP
