China’s foreign minister has said Beijing will “take all necessary measures” to defend the rights and interests of Chinese companies such as Huawei, which is locked in an escalating legal dispute with the US.

Beijing’s top diplomat, Wang Yi, said in response to a question about the company suing the US: “It is not difficult to see that the recent actions against specific Chinese enterprises and individuals are not just judicial cases, but deliberate political suppression.

“We have and will continue to take all necessary measures to resolutely defend the legitimate rights and interests of Chinese enterprises and citizens,” he said, adding that Beijing supported “related companies” in defending themselves and refusing to be “silent lambs”.

On Thursday, Huawei filed a lawsuit in Texas, where its US headquarters are based, alleging that a US government ban on its products and services was unconstitutional. Huawei’s chief financial officer, Meng Wanzhou, also faces charges in the US over alleged fraud and violation of US sanctions on Iran.

Huawei’s lawsuit marks its most aggressive move yet in a campaign to rehabilitate its global image after the US lobbied allies to restrict the company from supplying equipment for 5G mobile technology networks. It is the world’s largest telecommunications equipment provider and a global leader in 5G and smartphones. Founded by a former military engineer, Ren Zhengfei, it has come under increasing scrutiny over possible connections with the Chinese government.

The company, in a global public relations push over the last few months, has insisted that it has never given and would never give information to the Chinese government. However under a national intelligence law the company would be required to cooperate with Chinese authorities if asked.

“Huawei is not owned, controlled, or influenced by the Chinese government. Moreover, Huawei has an excellent security record and programme. No contrary evidence has been offered,” said Song Liuping, Huawei’s chief legal officer.

The legal wrangling comes as the US and China remain locked in negotiations to end a bruising trade war kicked off by sanctions imposed by the US last July. US president Donald Trump has said he is optimistic that a deal will be reached soon. On Wednesday, Trump said talks were “moving along well”.

China has agreed to buy more US goods and is set to unveil a foreign investment law that will bar local governments for forcing foreign firms to transfer technology to local companies, one of Washington’s key grievances. But sticking points remain and Huawei may become a bargaining chip in the ongoing talks.

When asked last month if dropping charges against Huawei could be part of a trade deal, Trump said: “We’ll be making that decision.”

Last year, the US lifted a ban on Chinese tech firm ZTE, which Trump described as part of a larger trade deal the US was negotiating with China and his “personal relationship with president Xi.”

The lawsuit has a small chance of winning in court, experts say. But its chief purpose may be forcing the US to make its case against Huawei publicly.

“The payoff is mostly public relations. It shows Huawei will use the US legal system and allow it to show how it thinks it has been unfairly treated,” said Julian Ku, who teaches international law at Hofstra University.