China has denied U.S. claims that its government and military are mounting cyberattacks against Washington.
The Foreign Ministry in Beijing called the accusation "groundless" and warned they could harm prospects for cooperation.
A report released by the Pentagon on May 6 marked the first time the Obama administration has explicitly blamed Chinese officials for cyberattacks.
It said China is using its cybercapabilities to collect intelligence against U.S. diplomatic, economic, and defense programs, and is developing the skills needed for cyberwarfare.
The report also cited progress in Beijing's effort to develop advanced stealth aircraft and build an aircraft-carrier fleet.
David Helvey, the U.S. deputy assistant secretary of defense for East Asia, said China's "lack of transparency" could affect the "security calculations of others in the region."
Based on reporting by AP, Reuters, and "Foreign Policy"