Huawei is trying to turn the tide in its fight against the U.S. government's ban on its network equipment, which has effectively shut down the company's sales in the country. During a press conference in Shenzhen on Thursday morning, the company announced that it is suing the U.S. government in order to attempt to overturn the ban, which was effected in August of last year as part of the National Defense Authorization Act. The Act specifically names Huawei and its fellow Chinese rival, ZTE, as potential threats to U.S. national security.

Huawei claims that a provision in the law is unconstitutional, as it doesn't afford individual entities such as Huawei the right to a fair trial. Huawei has been accused by the previous and current U.S. governments of having ties to the ruling Communist Party in China, and that it may be pressured to include vulnerabilities in its network equipment that could make it easier for China to commit acts of espionage.

The lawsuit comes only a few days after its chief financial officer, Meng Wanzhou, filed a civil suit against Canada's police and border security divisions, claiming "unlawful interrogation" in the run-up to her arrest at the Vancouver airport on December 1. She was arrested by Canadian authorities on behalf of the U.S. government, and has been charged with financial fraud and theft of trade secrets. She is being accused of helping her company forge network equipment deals with the Iranian government, in direct violation of U.S. sanctions.

Huawei's lawsuit against the U.S. government comes at a time when it's also being heavily scrutinized by other Western countries; its 5G equipment has also been banned in Australia and New Zealand, and the U.S. has put tremendous pressure on allies like Canada, the UK, Poland, and others to do the same. Huawei contends that it has never and will never open its equipment up to spying, and that it has complied with transparency laws in all of the countries in which it operates.

The snafu also comes at a time when Huawei is growing its handset business at a fast clip, outpacing much of the industry on its way to overtake Apple as the number two vendor in the U.S. last year. Its executive team has said many times in recent months that they believe Huawei will surpass Samsung as the top-selling smartphone manufacturer within three years.

But network equipment is where the company makes much of its profits, and while its U.S. ban has not prevented its growth in other parts of the world, it has marred its reputation. Recently, the company launched a Twitter account, Huawei Facts, that uses well-worn PR tropes to push back against negative public opinion.

In the meantime, the lawsuit may force the U.S. government to provide the evidence of malfeasance that it claims to have on the Chinese networking giant.