"It is important to note the overlay of law, regulation, policy, procedure, technical safeguards, training, culture, and ethos in the use of such tools; all of these things govern how NSA deploys various foreign intelligence techniques to help defend the nation," the NSA said.
The latest reports of the NSA's spying on Huawei follow earlier news stories about efforts to place backdoors on equipment from the company.
In December last year, Der Spiegel published a report outlining how the NSA intercepts deliveries of new computer equipment en route to plant spyware. The operation was conducted by the NSA's Office of Tailored Access Operations (TAO), which specializes in infiltrating computers, according to the report.
The newest reports this weekend say that the TAO unit by 2010 gained access to Huawei headquarters and was able to collect communications from Ren Zhengfei, the company's founder.
The Times story, however, pointed out that none of the documents leaked by Snowden show that NSA operations proved a specific link between Huawei and the PLA.
U.S. government officials for years have suspected that Chinese networking companies have worked with the PLA. For example, a congressional committee concluded an inquiry in 2012 with members still in doubt about the security of networking equipment from Huawei and ZTE
The U.S. government has also blocked efforts by Huawei to expand its business in the country. In September 2011, for example, the U.S. Department of Commerce said it had told Huawei that the company was barred from participating in a project to build a national wireless network.
Last October, Huawei issued a company report on cyber security in which it suggested ways companies could work together internationally to secure networks from hacking.
"We can confirm that we have never been asked to provide access to our technology, or provide any data or information on any citizen or organization to any Government, or their agencies," Huawei Deputy Chairman Ken Hu said in the report.
In an online article Saturday, The New York Times quoted William Plummer, a U.S.-based Huawei executive, as saying: "If such espionage has been truly conducted then it is known that the company is independent and has no unusual ties to any government, and that knowledge should be relayed publicly to put an end to an era of mis- and disinformation."
In addition to selling networking equipment, Huwaei is also the third-largest vendor of smartphones in the world. However, as recently as Mobile World Congress last month, a Huwaei official confirmed that the company has essentially given up on the network infrastructure business in the U.S., which makes efforts to sell mobile devices in the country more difficult.