Brent crude prices dropped 0.51% to trade at $40.58 a barrel, after rising 2.5% on Wednesday.
China increased its order on energy and farm purchases ahead of a review of the Sino-U.S. trade deal.
The El Sharara Oil Field in Libya has recommenced operation after a three-month siege by militants shut down operations.
Donald Trump called on OPEC to lower oil prices because the world cannot handle a hike.
Global oil prices have risen for the first time in 2019, thanks to a wide array of global events.