Donald Trump threw his support behind King Salman and Prince Muhammad bin Salman before travelling to South Korea as part of his tour of Asia

President Trump has given his direct support to the purge of royals, businessmen and officials under way in Saudi Arabia, tweeting his backing for the king and all-powerful crown prince.

“I have great confidence in King Salman and the crown prince of Saudi Arabia, they know exactly what they are doing,” he wrote, as he prepared to leave Japan for South Korea on the next leg of his Asia tour. “Some of those they are harshly treating have been ‘milking’ their country for years!”

Crown Prince Muhammad bin Salman, who is also defence minister and head of most of the most important policy councils in Saudi Arabia, is assumed to be the driving force behind the arrests at the weekend.

At least 11 princes, four