U.S. President Donald Trump held talks with top advisers to discuss the pressure campaign on Venezuela, a senior U.S. official said. On Saturday, Trump said the airspace above and surrounding Venezuela should be considered "closed in its entirety," but gave no further details.

Meanwhile, on Sunday, OPEC+ reaffirmed a small oil output increase for December and a pause in increases in the first quarter of next year due to rising fears of a supply glut.

"Fundamentals tend to rule over the longer term, and we still view this deterioration in the global balances as capable of forcing oil values lower with probabilities in WTI and Brent respectively to the $55 and $59 areas still quite high," Ritterbusch added.