Under UN embargo rules, North Korea is allowed to export a specific amount of coal.

Pursuant to paragraph 26 (b) of resolution 2321 (2016), total exports to all Member States of coal originating from the DPRK shall not exceed the aggregate of 400,870,018 US dollars or 7,500,000 metric tons, whichever is lower, between 1 January 2017 and 31 December 2017.

Member states are required to file reports to the UN on their North Korean coal imports.

The newest reports are an eye opener:

That’s right — 0 tons of North Korean coal were reported as imports by UN members in April.

Of course, there is gaming of the system going on. Last year Chinese companies busted the volume and dollar limits on North Korean coal and while China has imposed a “ban” on North Korean coal, it seems almost certain that some quantity of DPRK coal is entering China. And there is evidence that some North Korean coal ships have been allowed to dock and offload in China.

The real issue, however, is the limit set by the UN. By that metric, it appears that the screws are being tightened on Pyongyang, though not so much as to bring about the economic collapse that China fears.