SEATTLE • Huawei Device and Huawei Device USA have pleaded not guilty to United States fraud, trade secrets conspiracy and other charges, and a trial date has been set for March next year, the Justice Department said.

The units of China's Huawei Technologies were arraigned in a District Court in Seattle on Thursday, and Chief US District Judge Ricardo Martinez set trial for March 2 next year.

The two companies were charged in an indictment unsealed earlier this year that they conspired to steal T-Mobile trade secrets between 2012 and 2014.

The charges have added to pressure from the US government on Huawei Technologies, the world's biggest maker of telecommunications equipment.

Washington is trying to prevent American companies from buying Huawei routers and switches and is pressing allies to do the same.

T-Mobile had accused Huawei of stealing the technology called Tappy, which mimicked human fingers and was used to test smartphones.

Huawei has said the two companies settled their disputes in 2017.

Separately, federal prosecutors in Brooklyn have charged Huawei and its affiliates with bank and wire fraud on allegations that they violated sanctions against Iran.

An arraignment date is yet to be set in that case, which has added to Washington's tensions with Beijing.

A senior US cyber official said on Tuesday that European governments were listening to the US message that Huawei exposes telecommunications networks to security risks.

No evidence of the securities risks have been presented publicly, even as scrutiny on Huawei has intensified and the company has denied Beijing could use its technology for spying.

The increasing scrutiny prompted Huawei to run a full-page advertisement in major US newspapers on Thursday urging readers not to believe "everything you hear" about the Chinese tech firm.

Huawei touted its relief efforts in disaster-torn countries such as Chile and Indonesia, and also its work to connect the underserved around the world.

"Our doors are always open. We would like the US public to get to know us better," the advertisement states, noting that the US government has "developed some misunderstandings about us".

The advertisement ran in The Washington Post, The New York Times, The Wall Street Journal, Politico, USA Today and the Los Angeles Times, said Huawei spokesman Chase Skinner.

"I think it's more being transparent. It's time to take control of our narrative," said Mr Skinner, who noted that Huawei buys US$11 billion (S$15 billion) in US goods every year."

The move is part of an unprecedented public relations blitz, launched last month with a 25-minute interview aired on state-controlled China Central Television (CCTV) with Huawei chief executive Ren Zhengfei. In the CCTV segment, Mr Ren shrugs off the global push against his company.

The company later also did interviews with Britain's BBC and American broadcaster CBS.

REUTERS