BEIJING, April 13 (UPI) -- China is tightening sanctions against North Korea, as March trade with Pyongyang was up 20 percent over last year.
Huang Songping, a spokesman for China's General Administration of Customs, announced Wednesday total trade with North Korea totaled $491.8 million in March, up 20 percent from March 2015, Yonhap reported.
The data is raising questions regarding China's effective implementation of international sanctions, adopted by the United Nations Security Council on March 2.
But Beijing's customs agency said the enforcement of trade embargoes did not go into effect until April.
First-quarter China-North Korea trade was about $1.2 billion, up 12.7 percent from the first quarter of 2015.
Chinese exports to the North rose 14.7 percent, and North Korea imports to China were up 10.8 percent in the first quarter.
The data suggests Pyongyang's various provocations, which included a Jan. 6 nuclear test, a Feb. 7 ballistic missile launch and other signs of belligerent behavior bore little to no impact on Chinese trade with North Korea, South Korea press reported.
The statistics also challenge reports that have suggested China had been turning away North Korean coal imports.
Hwang told reporters Wednesday China has been importing North Korean anthracite coal and apparel.
But North Korea's coal exports have been struggling since China cracked down on coal as a source of fuel to combat pollution in 2015, and commodity prices have dropped by more than 20 percent for coal and about 31 percent for iron ore.
William Brown, an adjunct professor at Georgetown University's School of Foreign Service and a non-resident fellow at the Korea Economic Institute of America, noted in a recent analysis North Korea earned more than $1 billion from anthracite coal exports to China in 2015.
North Korean military units manage the sales, Brown wrote.