A Huawei store in Beijing. (Mark Ralston/AFP/Getty Images)

China demanded a U.S. explanation Monday about reports that the National Security Agency infiltrated Chinese telecommunications giant Huawei Technologies to see whether it was spying for Beijing and to turn its equipment against other countries, such as Iran.

“China has lodged complaints to the United States about this many times. We urge the U.S. side to make a clear explanation and stop this kind of acts,” said China Foreign Ministry spokesman Hong Lei. He said China was “gravely concerned” about reports of “eavesdropping, surveillance and stealing of secrets by the United States.”

The NSA operation to hack into Huawei was disclosed by the New York Times this weekend based on leaked documents obtained from former NSA contractor Edward Snowden. According to one classified 2010 document published Saturday, the NSA believed that “many of our targets communicate over Huawei-
produced products, we want to make sure that we know how to exploit these products — we also want to ensure that we retain access to these communication lines, etc.”

Because Huawei’s Chinese-made equipment has often been sold to countries that are also of particular national security interest to the United States, the NSA proposed using Huawei equipment to penetrate the networks of countries such as Iran, Afghanistan, Pakistan, Kenya and Cuba, according to the document.

Among information obtained by the NSA, the report said, was data about how the company’s routers worked and communications of Huawei’s top executives.

Huawei issued a statement Monday saying, “If the actions in the report are true, Huawei condemns such activities that invaded and infiltrated into our internal corporate network and monitored our communications.”

The statement also said, “Huawei disagrees with all activities that threaten the security of networks and is willing to work with all governments, industry stakeholders and customers, in an open and transparent manner, to jointly address the global challenge of network security.”

The report comes after nine months of disclosures about NSA surveillance based on documents leaked by Snowden that have greatly diminished trust in the agency and hurt U.S. technology companies that cooperate under court order with the NSA.

It also comes as the Obama administration has sought to confront China on reducing cyber-­conflict and Chinese industrial cyber-espionage. For several years, the United States has been concerned about Chinese hacking of U.S. industry to steal commercial and military secrets.

The report, many experts noted, came just days ahead of Monday’s high-level meeting between President Obama and Chinese President Xi Jinping. Last year, reports based on the first batch of leaked documents from Snowden were released days before a meeting between Obama and Xi in Sunnylands, Calif.

Some, including Jin Canrong, associate dean of international studies at Renmin University in Beijing, believe the leak this weekend was deliberately timed — whether by Snowden or other players on the global stage — for maximum effect on U.S. international relations. One result of Snowden’s disclosures, Jin noted, is an improved position for China in its fight with the United States over cybersecurity and allegations of Chinese hacking.

Ellen Nakashima in Washington and Liu Liu in Beijing contributed to this report.