China’s Ministry of Transport instructed the country’s ports to keep out North Korean ships listed under the most recent UN Resolution, a document provided to NK News by a Chinese port authority reveals.

Many North Korea watchers noted that successful implementation of Resolution 2270 passed on March 2, but the letter circulated to port authorities three days later indicates Beijing were quick to implement the designations.

“By the Resolution 2270 of 2nd March 2016, the UN Security Council voted to impose sanctions against North Korea, requiring all member states’ ports to detain the 31 vessels belonging to OMM