The biggest concerns of the outgoing OPEC chief

        
The U.S.-China trade war and booming American shale production are among the top worries for the United Arab Emirates' energy minister and former OPEC president.

After a volatile year for oil prices, hydrocarbon-exporting countries are buckling down for what could be more turbulence ahead.
In terms of geopolitical headwinds for 2019, "One is the potential of heated war between China and the United States," Suhail Al Mazrouei told CNBC's Hadley Gamble on Wednesday. Mazrouei finished his term at the helm of OPEC on January 1.
"We're not playing with President Trump or any other president," he said.
I think this is one fundamental, not only affecting us but affecting the whole economics of the world. And I tend to be... more optimistic that we are not going to see a war. It's negotiation tactics, they will end on a resolution, whatever it takes, this year or next year. " While cautiously optimistic on the outcome of ongoing trade negotiations between the world's two largest economies, Mazrouei stressed the impact of U.S. shale production on the market — something that's increasingly putting OPEC members under pressure. "But this is one thing, how much is coming from the shale oil production I think that's another factor we need to watch and we need to advise that it has to be reasonable," the minister said.