The leaders of a congressional probe into two Chinese telecom giants expressed fresh concerns Thursday about the firm's links to the Beijing government, as the companies defended their integrity.
The House Intelligence Committee opened a hearing into "security threats" posed by China's Huawei and ZTE, as part of a probe begun last year.
Committee chairman Mike Rogers said he has been "disappointed" that the firms have provided little evidence to prove they are not being used by the Chinese government for espionage or cyber attacks on the United States.
"We must get to the truth and see if these companies are tied to or influenced by the Chinese government," Rogers said as the hearing opened.
Representative Dutch Ruppersberger expressed similar concerns, saying the firms so farm have produced "a lack of direct responses and vague answers" to inquiries from the committee.
Ruppersberger said he was concerned that Chinese products are subsidized by the Beijing government and that "US consumers may have no idea about the national security implications of their purchases."
Charles Ding, a corporate senior vice president of Huawei, told the panel: "I am here today to set the record straight about Huawei," and added that the firm's success "has been built on entrepreneurship... not on favoritism from any government."
"Our customers throughout the world trust Huawei," Ding said in his prepared remarks.
"We will never do anything that undermines that trust. It would be immensely foolish for Huawei to risk involvement in national security or economic espionage... Huawei has not and will not jeopardize our global commercial success nor the integrity of our customers' networks for any third party, government or otherwise. Ever."
Zhu Jinyun, ZTE's senior vice president for North America and Europe, defended his firm's integrity.
"ZTE is focused on its success as a multinational company," he said.
"ZTE is not an SOE (state owned enterprise) or government controled. Indeed, ZTE is China's most independent, transparent, globally focused, publicly traded telecom company."
Zhu said he found committee suggestions that it is being used for cyber attacks "very disturbing."
"The committee's central question has been: would ZTE grant China's government access to ZTE telecom infrastructure equipment for a cyber attack?... Let me answer emphatically: No!" he said.
"China's government has never made such a request. We expect the Chinese government never to make such a request of ZTE. If such a request were made, ZTE would be bound by US law."
Explore further: Briefs: Cisco, ZTE join in China telecom effort