WASHINGTON—President Donald Trump, using Twitter again to criticize a company he once hailed as a “true American icon,” gave his backing to a boycott of Harley-Davidson motorcycles if the company moves some production out of the U.S.

“Great,” the president said in a tweet. “Most other companies are coming in our direction, including Harley competitors. A really bad move! U.S. will soon have a level playing field, or better.”

Trump has lashed out more than a half-dozen times against the Milwaukee-based maker of the iconic motorcycles after praising the company early in his presidency. The relationship flipped after Harley announced plans earlier this summer to shift production of bikes destined for Europe to overseas facilities.

It acted after Trump’s administration imposed steel and aluminum tariffs that promoted retaliatory measures from the European Union that Harley-Davidson said would increase its costs by $2,200 for each bike shipped there.

For more about Harley and tariffs, read chief editor John Sprovieri's editorial from the August 2018 issue.