China said on Friday that any allegations that it was involved in breaking into US government computers are irresponsible.
Chinese Foreign Ministry spokesman Hong Lei said at a regular news briefing that Beijing hopes the US would be "less suspicious and stop making any unverified allegations, but show more trust and participate more in cooperation."
US officials say China-based hackers are suspected of breaking into the computer networks of the US government personnel office and stealing identifying information of at least 4 million federal workers.
Beijing routinely dismisses any allegation of its official involvement in cyberattacks on foreign targets, while invariably noting that China is itself the target of hacking attacks and calling for greater international cooperation in combating hacking.
"We know that hacker attacks are conducted anonymously, across nations, and that it is hard to track the source," Hong said. "It's irresponsible and unscientific to make conjectural, trumped-up allegations without deep investigation."
China's military is believed to have made cyber warfare capabilities a priority more than a decade ago. One of the few public announcements of the capabilities came in a May 25, 2011, news conference by Defense Ministry spokesman Geng Yansheng, in which he spoke of developing China's "online" army.