SINGAPORE (Reuters) – China National Petroleum Corp has halted August loadings of Venezuelan oil following the latest set of U.S. sanctions on the South American exporter, two Beijing-based senior sources with direct knowledge of the matter told Reuters on Monday.

The Trump administration in early August froze all Venezuelan government assets in the United States and U.S. officials ratcheted up threats against companies that do business with Venezuela.

A CNPC spokesman did not immediately respond to Reuters’ requests for comment.

“Trump’s executive order gave a directive for the follow-up sanction measures that shall be announced by the U.S. Treasury… CNPC is worried that the company is likely to be hit by the secondary sanctions,” said one source.

A second person, an executive with a key marketer of Venezuelan oil in China, said his company was notified of the suspension.

The two sources declined to be identified as they are not authorised to speak to the media.