The United States ambassador to China, R. Nicholas Burns, criticized the espionage law on Tuesday.

“This is a law that potentially could make illegal in China the kind of mundane activities that a business would have to do to seek due diligence before you agree to a major investment deal,” he said.

It appears that European firms have not attracted the attention of China’s security establishment, as Europe’s national leaders have generally taken a more accommodating stance toward China than the Biden administration. But European companies also say it is critical to maintain public access to information about markets and companies.

“There is a strong need for clarification on which information is sensitive and which is not,” said Joerg Wuttke, the president of the European Union Chamber of Commerce in China.

Dan Harris, a Seattle-based lawyer who works with foreign companies in China, said that in the past week he had heard from at least two American companies looking to leave the country, having seen the signs that the Chinese Communist Party appears to be sending with the recent scrutiny.

“The message is: ‘We don’t care that much about the economy. What we care about is keeping you in line,’” Mr. Harris said. “‘And if you don’t do what we want you to do, we will come after you.’”

Ana Swanson and Edward Wong contributed reporting.