The US National Security Agency infiltrated servers at the headquarters of Chinese telecommunications giant Huawei Technologies Co, obtaining sensitive information and monitoring the communications of top executives, according to the New York Times and the German magazine Der Spiegel.

The Times said the operation, code-named "Shotgiant," was based on NSA documents provided by Edward Snowden, the former agency contractor who has leaked data revealing sweeping US surveillance activities.

One of the goals was to find any connections between Huawei and the Chinese People's Liberation Army, according to a 2010 document cited by the newspaper.

But it said the operation also sought to exploit Huawei's technology. It said the NSA aimed to conduct surveillance through computer and telephone networks Huawei sold to other nations. If ordered by the US president, the NSA also planned to unleash offensive cyber operations, it said.

The newspaper said the NSA secured access to the servers in Huawei's sealed headquarters in the Chinese city of Shenzhen and got information about the workings of the routers and digital switches the company says connect a third of the world's people. The NSA also tracked the communications of Huawei's top executives, the Times reported.

Der Spiegel said the NSA breached Huawei's computer network and copied a list of more than 1,400 clients and internal training documents.

"We have access to so much data that we don't know what to do with it," the magazine cited an NSA document as saying.

Digital offensive

Der Spiegel said the NSA was also pursuing a digital offensive against the Chinese leadership.

The Times quoted the NSA document as saying: "Many of our targets communicate over Huawei-produced products. We want to make sure that we know how to exploit these products," to "gain access to networks of interest" around the world. In the document, an analyst wrote: "If we can determine the company's plans and intentions, we hope that this will lead us back to the plans and intentions" of the Chinese government.

The Times also reported that as Huawei invested in new technology and laid undersea cables to connect its US$40 billion-a-year networking operation, the NSA was interested in getting information on key Chinese customers, including "high priority targets — Iran, Afghanistan, Pakistan, Kenya, Cuba."

The Times quoted William Plummer, a senior Huawei executive in the United States, as saying the company did not know it was an NSA target.

"The irony is that exactly what they are doing to us is what they have always charged that the Chinese are doing through us," the Times quoted him as saying.

If such espionage had been carried out then it is known that the company is independent and has no unusual ties to any government, Plummer was quoted as saying.

US officials acknowledge that in the course of assessing the economic prospects or stability of foreign countries, US agencies might collect data on individual companies.

They have also said the US might collect data on foreign companies in preparation for imposing economic sanctions or taking other foreign policy-related actions against a country and its leadership, but not to aid American companies.