Coal is North Korea's financial lifeline, according to The Washington Post, which reported on the announcement. The commodity is North Korea's single largest export item, while North Korea is China's fourth largest supplier of the fuel.
Although the world's second largest economy offered no explanation for the cut-off, China has been under international pressure to help moderate North Korea's increasingly aggressive actions since Kim Jong-un took over the hermit kingdom in 2011.
China's ban could help put international sanctions aimed at North Korea's nuclear weapons efforts into fuller force.
Kim Jong-nam died in Malaysia earlier this week, though he had been living in the former Portuguese colony of Macau. The city is now a special administrative region under China, and experts say Kim Jong-nam received protection from the Chinese government as a result.