China claims that about two-thirds of the cyberattacks against its military sites have come from the US.
The Chinese Ministry of Defence has accused the US of being the biggest attacker of its military networks last year.
Chinese ministry spokesman Geng Yansheng was quoted by Reuters as saying that, "The Defence Ministry and China Military Online websites have faced a serious threat from hacking attacks since they were established, and the number of hacks has risen steadily in recent years."
"According to the IP addresses, the Defence Ministry and China Military Online websites were, in 2012, hacked on average from overseas 144,000 times a month, of which attacks from the U.S. accounted for 62.9 percent," Yansheng said.
Yansheng said he had noted reports that the US planned to expand its cyber-warfare capability but that they were unhelpful to increasing international cooperation towards fighting hacking.
The claims from Yansheng follows allegations by the US security firm, Mandiant, which said a secret military unit in Shanghai is linked to an attack on some American companies' websites.
China denied the allegations by Mandiant and said the country never supports cyber-attacks and it has been a major victim of cyber attacks, particularly by the US.