Trump's five-day trip to Scotland will see him celebrating the opening of his new 18-hole course in Aberdeen, while he continues to press to bring the British Open to his Turnberry course.

His private visit is exceptional as US presidents rarely promote their personal interests so publicly while in office.

The U.S. president is due to visit Trump-owned golf courses in Scotland and meet informally with the British prime minister over the U.S.-U.K. trade deal.