Hong Kong (CNN Business) Embattled Chinese tech company Huawei is fighting back against new restrictions from the US Federal Communications Commission that further limits what little business it has left in the United States.

Huawei, the world's largest telecommunications equipment maker and a leading smartphone brand, said Thursday that it has filed a lawsuit in New Orleans challenging a recent FCC decision that prohibits American carriers from using federal subsidies to purchase Huawei equipment.

Song Liuping, Huawei's chief legal officer, said at a press conference Thursday that FCC chairman Ajit Pai is targeting Huawei because it "is a Chinese company, that's his only excuse."

"He has tried to spread fear about Huawei. He uses words like 'back door' to scare people, but offers no proof," Song added.

Huawei's lawsuit argues that the FCC order is unlawful because it gives no evidence of the national security threat that the company poses, which is in violation of the US Constitution and other laws. The company has made similar arguments in other litigation against the US government.