Chinese hackers tried to penetrate specific State Department email accounts in the weeks before Secretary of State Antony J. Blinken traveled to Beijing in June, U.S. officials said on Wednesday.

The investigation of the efforts by the Chinese hackers, who likely are affiliated with China’s military or spy services, is ongoing, American officials said. But U.S. officials have downplayed the idea that the hackers stole sensitive information, insisting that no classified email or cloud systems were penetrated. The State Department’s cybersecurity team first discovered the intrusion.

Multiple officials said the attack was targeted at individual email accounts, rather than a large-scale exfiltration of data, which Chinese hackers are suspected of having done before. Biden administration officials declined to identify which officials had been targeted by the Chinese hackers.

Microsoft, which disclosed the hack on Tuesday, said that the hack began in May, according to their investigation, and was discovered on June 16, just ahead of Mr. Blinken’s trip to Beijing. He departed from Washington that evening. The trip was critical for both Washington and Beijing: It was the first visit to China by a U.S. secretary of state in five years and was aimed at establishing high-level channels of communication and improving deteriorating relations. Since then, Treasury Secretary Janet L. Yellen has visited Beijing, and John Kerry, the special climate envoy, plans to land there on Sunday for four days of talks.