The US Department of Justice has filed a series of criminal charges against Huawei, the Chinese telecommunications giant, and its chief financial officer, Meng Wanzhou.
The charges include bank fraud, law obstruction, and technology theft.
The events will probably sharpen the tensions between the United States and China, already inflamed by the commercial war.
Both Meng and Huawei denied the allegations.
Meng had been arrested in Canada last month at the request of the United States, triggering a series of retaliations by parts of the Chinese government against Canadian citizens (two arrests without charges and the commutation of a 15-year sentence to the death penalty for a third Canadian citizen).
The arrest of Meng Wanzhou had been requested for allegedly evading sanctions on Iran.
The secretary of the US Department of Commerce, Wilbur Ross said that for years, Chinese companies have bypassed export laws, and have undermined sanctions, often using US financial systems to facilitate their illegal activities.
According to the allegations, Huawei misled a global bank and the US about its relationship with two subsidiaries, Huawei Device USA and Skycom Tech, to conduct business with Iran.
Other accusation concern the theft of technology from T Mobile, used to test the durability of smartphones, as well as obstructing justice and committing wire fraud.
“These charges lay bare Huawei’s alleged blatant disregard for the laws of our country and standard global business practices,” said FBI Director Christopher Wray.