WASHINGTON — The Trump administration is exacerbating an already antagonistic relationship with the European Union just when global health experts and economists are calling for a coordinated global response to the coronavirus.

The administration’s surprise decision on Wednesday to ban travelers from the European Union, but not Britain, where diplomatic relations are better, has prompted speculation that political motivations could underlie the move. President Trump attributed the exception to Britain’s “very strong borders” and its “very good job” fighting the virus.

For now at least, the United States is on course to intensify trading tensions with Europe next week.

A proposed increase in tariffs on the European plane maker Airbus is scheduled to go into effect on Wednesday, raising costs for airlines now struggling with mounting losses. A visit to Washington next week by the European Union trade commissioner, Phil Hogan, which might have paved the way toward a resolution, has been canceled.