A U.S. Defense Department report Monday said "numerous" computer systems were targeted by the Chinese government or its military, including computer networks operated by the U.S. government.
U.S. security company Mandiant published a report in February stating that it traced cyberattacks on U.S. companies and government agencies to the Chinese military.
The Defense Department said it suspected China was trying to extract information about U.S. defense programs for its own gain.
"This unwise move is not only self-contradictory as Washington has been claiming to boost military ties with China but also harmful to the aspiration of both countries to forge a cooperative partnership based on mutual respect, mutual benefit and a win-win situation," an editorial published in Xinhua said Tuesday.
Xinhua said the U.S. Defense Department was resorting to Cold War mentalities, noting its own cyber analyses found its computer networks were likely targeted by the Pentagon.
The report cited 2011 comments by U.S. President Barack Obama, who said his country enjoyed a "healthy, stable and reliable military-to-military relationship" with China.