Related

Revelations about the potential OPM hacking came as Secretary of State John Kerry was wrapping up a three-day meeting in Beijing known as the U.S.-China Strategic and Economic Dialogue, intended to foster talks between the two countries.

Mr. Kerry on Wednesday raised U.S. concerns about other alleged instances of China’s cyberespionage with Chinese State Councilor Yang Jiechi at high-level talks in Beijing, urging the government to restart a special working group on the issue. China canceled the special working group after U.S. prosecutors indicted five Chinese military officers in May for cybertheft.

“These issues are sufficiently important to warrant us rolling up our sleeves and tackling them,” a senior U.S. administration official said after Mr. Kerry’s meeting, adding that U.S. officials in meetings described “our concerns and our hope that the Chinese will themselves take necessary action to put an end to this kind of activity.”

The U.S. indictment in May focused on hacking of corporate secrets, detailing how five officers in what is known as Unit 61398 of the People’s Liberation Army in Shanghai allegedly hacked five U.S. companies and a labor union, stealing information like details of piping systems for nuclear-power plants.

U.S. officials say the individuals were attempting to gain access to trade secrets and other information that would help the Chinese compete and gain an advantage in situations like negotiations to build a nuclear-power plant in China or during trade talks. The Justice Department named as victims a number of brand names from American industry, including U.S. Steel Corp., Westinghouse Electric Co. and Alcoa Inc.

The breach of computer systems at the Office of Personnel Management is notable because it appeared to be a deliberate attempt to steal U.S. government secrets, even if its success was uncertain. The Obama administration has focused its criticism primarily on China’s pursuit of commercial secrets, in an effort to differentiate that hacking activity from the traditional government spying that all countries pursue, including the U.S. But in U.S. military and intelligence circles, frustration has also mounted over suspected Chinese theft of government secrets.

—Ian Talley contributed to this article.

Write to Andrew Grossman at andrew.grossman@wsj.com and Siobhan Gorman at siobhan.gorman@wsj.com

See also: The New York Times
Chinese Hackers Pursue Key Data on U.S. Workers
http://www.nytimes.com/2014/07/10/world/asia/chinese-hackers-pursue-key-data-on-us-workers.html?_r=0

Part of the building of 'Unit 61398', a secretive Chinese military unit, is seen in the outskirts of Shanghai February 19, 2013. The unit is believed to be behind a series of hacking attacks, a U.S. computer security company said, prompting a strong denial by China and accusations that it was in fact the victim of U.S. hacking. REUTERS/Carlos Barria (CHINA - Tags: POLITICS SCIENCE TECHNOLOGY MILITARY) - RTR3DZ82

Part of the building of ‘Unit 61398′, a secretive Chinese military unit, is seen in the outskirts of Shanghai February 19, 2013. The unit is believed to be behind a series of hacking attacks, a U.S. computer security company said, prompting a strong denial by China and accusations that it was in fact the victim of U.S. hacking. REUTERS/Carlos Barria 

U.S. Army Gen. Martin E. Dempsey (left), chairman of the Joint Chiefs of Staff, shakes hands with his Chinese counterpart, Gen. Fang Fenghui, who is chairman of the General Staff, during their press briefing at the Bayi Building in Beijing on Monday, April 22, 2013. Gen. Fang said Beijing firmly opposes the North’s nuclear weapons program and wants to work with others on negotiations to end it. (AP Photo/Andy Wong, Pool)