SHENZHEN, China — Huawei said on Thursday it was suing the United States for barring government agencies from buying the Chinese telecom giant’s products, opening a legal front in its battle against American warnings that they could serve as a tool for Chinese intelligence services.

Huawei said the suit was filed in a US District Court in Plano, Texas, challenging a 2019 US defence bill that prevents US government agencies from buying the company’s equipment and services, as well as working with third parties that are Huawei customers.

"The US Congress has repeatedly failed to produce any evidence to support its restrictions on Huawei products. We are compelled to take this legal action as a proper and last resort," Huawei’s rotating chairman Guo Ping said in a statement.

"If this law is set aside, as it should be, Huawei can bring more advanced technologies to the United States and help it build the best 5G networks."

Guo said the company was seeking unspecified damages for what he called "unconstitutional" restrictions.

"The US government is sparing no effort to smear the company," he said at a news conference at the company’s headquarters in the southern city of Shenzhen.

Guo even countered that the US government "has hacked our servers and stolen our emails and source code", without providing details.

The United States says Huawei equipment could be manipulated by China’s Communist government to spy on other countries and disrupt critical communications.

Washington is urging governments to shun the company just as the world readies for the advent of ultra-fast 5G telecommunications, an advancement that Huawei was expected to lead and which will allow wide adoption of next-generation technologies like artificial intelligence.

Huawei has responded with an aggressive PR campaign to counter the US warnings, with reclusive founder Ren Zhengfei denying the claims in a series of foreign media interviews.

The charm offensive went into another gear on Wednesday as Huawei welcomed news organisations on a tightly guarded tour of its massive production lines and research and development facilities in southern Guangdong province.

Huawei’s Chief Financial Officer Meng Wanzhou, Ren’s daughter, faces potential extradition from Canada to the United States over charges of Iran sanctions violations.

The US Justice Department accuses Huawei and Meng of circumventing US sanctions against Iran. Two affiliates also have been charged with stealing trade secrets from telecommunications group T-Mobile.

Meng faces a May 8 hearing in Vancouver, where she was arrested while changing planes.

Two Canadians have been detained in China in suspected retaliation over her arrest.

Huawei is the world leader in telecoms networking equipment.

But its dominance has increasingly caused concern in Washington, which fears that Beijing could use security "backdoors" to gain access to networks for spying or other purposes.

These concerns have been fueled by Ren’s background -- he is a former Chinese army engineer -- and a law recently enacted by Beijing that obliges Chinese companies to aid the government on issues affecting national security. — AFP