BEIJING — The Chinese technology giant Huawei said on Tuesday, without providing evidence, that the United States government had pressured the company’s employees to turn against it and had used cyberattacks to infiltrate the firm’s computer systems in recent months.

The company, which makes smartphones and equipment for telecommunications networks, has been the focus of an intense legal and political campaign by the Trump administration, which says Huawei products could be used by the Chinese government for spying or sabotage.

But in a news release on Tuesday about an unrelated allegation of patent infringement, Huawei said that the United States had recently expanded its offensive against the company.

In the past several months, the company said, American authorities had masqueraded as Huawei workers to “establish legal pretense for unfounded accusations against the company,” although it did not say what the accusations were.