Richard Branson, the founder of Virgin Atlantic, sharply criticized President Trump’s “erratic” trade policies on Wednesday, saying that they risk “doing so much damage around the world” and that most Americans do not support them.

“The unpredictability is just awful for everybody around the world,” Mr. Branson told reporters from British news outlets during a business trip to Saudi Arabia. “It’s just erratic, unpredictable, which is very, very difficult for business to deal with.”

He added: “An unsettled world is not good for anybody. People delay decisions on investment and spending.”

Mr. Branson’s comments were striking because many business leaders have avoided direct public criticism of Mr. Trump, apparently for fear of antagonizing his administration.

By contrast, Mr. Branson directly spoke out against the president’s policy of imposing heavy tariffs on most imports to the United States, even on goods coming from close allies.

He also said Mr. Trump’s decision to essentially switch sides on the Ukraine war — by warming up to Moscow while pushing Ukraine to accept the loss of territory — “had put America on the wrong side of history” and “should worry the world the most.”

Mr. Branson, one of Britain’s best known business figures, spoke while visiting Riyadh to launch a Virgin Atlantic flight from Heathrow Airport in London to the Saudi capital. His comments were quoted by several outlets, including The Telegraph, The Times of London and the Financial Times.

The U.S. government’s tariff announcements had, Mr. Branson said, “financially done a lot of harm. The world was on the verge of a complete meltdown two weeks ago.”

The British entrepreneur said that he believed the president’s policy agenda was promoted by “a fairly small elite of people around Trump” but lacked the support of many Americans.

“I don’t think he’s carrying the vast majority of Americans in what he’s doing,” Mr. Branson said. “Most American people are decent individuals. I’m just sad, incredibly sad. And many, many, many Americans I know are just very sad.”