Photo: Xinhua

A Chinese Foreign Ministry spokesperson said on Wednesday that it is indeed ironic that the US National Security Agency (NSA), as the main implementer of the PRISM program and the world's largest cyber espionage agency, publicly accuses other countries of cyber espionage.

The comments came after US media outlets reported that the US agency had on Tuesday warned that Chinese government hackers were taking aim at US computer networks involved in national defense, constituting a threat "in need of urgent attention."

Foreign Ministry spokesperson Zhao Lijian said on Wednesday that it is a known fact the NSA has for years been engaged in the world's largest cyber attack and espionage, even targeting its own allies. 

In March, Chinese tech company 360 Security Technology publicized a series of attacks against China's aerospace, scientific research institutions, petroleum industry and large-scale internet companies by APT-C-39, a hacking organization affiliated with the Central Intelligence Agency for about 11 years. 

It's obvious which country is the victim of cyber spying, Zhao said. 

"Lies repeated a thousand times are still lies. The US, an 'empire of hacking', should immediately stop the old trick of a thief crying 'stop the thief'," Zhao said.