"It does not appear to have compromised any sensitive material," he said, but noted the action "harmed our business and threatened our nation's competitiveness."
Kerry was in attendance at an annual summit on Chinese-U.S. relations when information was publicly released about the March security breach, in which hackers accessed computer networks housing Office of Personnel Management information on federal employees. The breach was an apparent attempt to collect information on people who had applied for a top-secret security clearance.
An OPM official said "any loss of personally identifiable information" has not yet been identified.
The incident comes after five members of the China's People's Liberation Army were indicted in U.S. federal court in May for allegedly hacking into U.S. nuclear and manufacturing firms to steal trade secrets. It was the first time the United States brought cybersecurity-oriented charges against a foreign country, and was largely symbolic in that China and the United States have no extradition treaty.