The newly appointed U.S. Treasury secretary "pressed hard" in meetings with Chinese leaders over alleged Chinese cyber attacks aimed at stealing commercial secrets from American companies, according to U.S. officials.
Jack Lew raised the issue at a meeting on Wednesday with Li Keqiang, China's new premier, in the Pavilion of Purple Light in Beijing's central leadership compound, an official said.
"It has to be recognized, as the president indicated, this is a very serious threat to our economic interests," Mr Lew said after the meeting. "There was no mistaking how seriously we take this issue."
Mr. Lew's visit to Beijing, the first by a senior member of President Barack Obama's new cabinet, was timed to coincide with the formation of a fresh Chinese government, headed by Xi Jinping, who formally took over as state leader last week.
The meetings were the first in public for Mr. Xi and Mr. Li in their new roles and also Mr. Lew's opening meetings with foreign leaders since he was confirmed as Treasury secretary in February.
In his discussion with Mr. Li, Mr. Lew distinguished between cyber attacks suffered by many governments and hacking by state-sponsored Chinese entities aimed at stealing commercial secrets.
China has been accused by foreign governments, companies and cyber hacking experts of supporting large-scale efforts to extract trade and commercial secrets from global companies.