China on Friday reported a sharp drop in trade with North Korea in 2017.
China, the main source of North Korea's fuel, did not export any gasoline, jet fuel, diesel or fuel oil to its neighbour in November.
China is replacing coal-fired boilers with natural gas or electric boilers for winter heating in the north.
"Export prospects remain solid, given our outlook for growth globally, although more forceful USA trade restrictions on China's exports remain a key risk, following another rise in the U.S.' bilateral trade deficit in 2017", he said.
In December, China's exports jumped 10.9% from a year ago to $231.8 billion, down from a 12.3% pace in the previous month.
Buying eased in December as refiners and fuel distributors drew on inventories after hefty stockpiling in the previous month, said Seng-Yick Tee, analyst with SIA Energy.
Imports of soybeans hit their second-highest monthly total in December of 9.55 million tonnes, and a record 95.54 million tonnes for the year.
Experts say they fear the situation could deteriorate this year, though.
"Given no big surge in fuel exports and mild stock builds in strategic (crude oil) reserves, the crude data points to under-estimates in domestic fuel productions", Tee said.
Shipments of oil, gas, copper concentrate and iron ore all also set new record highs in 2017, as the world's top consumer of commodities continued to scoop up lower-priced raw materials to feed its vast heavy industry.
He estimated that, according to the American government's means of calculation - which usually produce higher balance numbers than the Chinese numbers - China's trade surplus against the USA may have reached $376 billion in 2017.
China's imports from North Korea plunged in December to their lowest level in dollar terms since at least the start of 2014, with trade curbed by United Nations sanctions aimed at persuading Pyongyang to abandon its ballistic missile and nuclear weapons programs.
China's exports to North Korea in December declined 23.4 percent from a year earlier to $260 million, Huang told reporters.
The Chinese data also showed that China's imports from North Korea fell 33% in 2017, a possible indication of Beijing's cooperation with the USA over Pyongyang, though China's exports to North Korea increased 8.3%.