Yellen, in Beijing, Criticizes China’s Treatment of U.S. Companies

“We are still evaluating the impact of these actions, but they remind us of the importance of building resilient and diversified supply chains,” Ms. Yellen said. She suggested that additional responses from the United States could be looming to ensure that American businesses and workers were treated fairly.

“I will always champion your interests and work to make sure there is a level playing field,” Ms. Yellen added. “This includes coordinating with our allies to respond to China’s unfair economic practices.”

Businesses are also alarmed by China’s ever-tightening national security laws, which include a stringent counterespionage law that took effect on Saturday. The U.S. State Department issued a warning this week advising Americans to reconsider traveling to China because of the possibility of wrongful detention.

Michael Hart, the president of the Chamber, said American companies are trying to play a constructive role in the economic relationship between the United States and China.

“We’ve been trying, regardless of what’s happened at the political level, to find common cause with our Chinese counterparts by employing, manufacturing, producing, buying, selling, paying our taxes and doing it all in a manner that reflects our values,” Mr. Hart, who was seated next to Ms. Yellen, said. “And we believe it also benefits the United States and China.”

The Treasury secretary planned to raise these issues during a blitz of meetings with top Chinese officials over the next two days.

Besides the business leaders, Ms. Yellen was also meeting on Friday with Liu He, China’s former vice premier, and Yi Gang, the outgoing governor of the People’s Bank of China. A Treasury Department official said that Ms. Yellen discussed the outlook for the economy in an informal discussion with her former counterparts that lasted more than an hour.

Later on Friday afternoon, she will meet with Premier Li Qiang at the Great Hall of the People.

Claire Fu contributed reporting.