U.S. companies are more optimistic than a year ago about business prospects in China despite a backdrop of escalating trade tensions and worries over regulation, according to the latest annual survey by the American Chamber of Commerce in China and Bain & Company.

The upbeat tone appears to reflect "strong growth across many sectors and for many companies during 2017 in China," as the nation's expanding consumer economy creates opportunities, said Stephen Shih, a partner with Bain who worked on the survey.