The US Justice Department has unveiled more than 20 charges against the Chinese telecommunications company Huawei, its chief financial officer and two affiliates.
In a 13-count indictment filed in New York, the US Justice Department said Huawei misled a global bank and US authorities about its relationship with subsidiaries Skycom Tech and Huawei Device USA Inc, in order to conduct business in Iran.
In a separate case, the Justice Department also accused two Huawei subsidiaries of 10 counts of stealing trade secrets, wire fraud and obstructing justice for allegedly stealing robotic technology from carrier T-Mobile US Inc to test smartphones' durability. Those charges were filed in the western district of Washington state.
Huawei did not respond to requests for comments on the charges.
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.
The charges in both cases add to US pressure on Huawei, the world's biggest telecommunications equipment maker.
The Trump administration is trying to prevent American companies from buying Huawei routers and switches and is pressing allies to do the same. US security experts are concerned the equipment could be used for spying.
Huawei's chief financial officer Meng Wanzhou - who is also the daughter of Huawei's founder, Ren Zhengfei - was arrested in Canada in December at Washington's request, and is now fighting extradition to the United States.
Ms Meng, who has denied the charges, is currently in Vancouver staying in one of her family's homes as she awaits a decision from a Canadian court on the US extradition request.
US authorities accuse her of playing a lead role in the scheme to use subsidiaries to conduct business in Iran in violation of US sanctions against Tehran.
The arrest ratcheted up tensions with China, which responded by arresting two Canadians on national security grounds.
Ren denies his company's products would be used by the Chinese government to spy.
US-China trade talks are set to resume shortly in Washington, although Commerce Secretary Wilbur Ross said the two cases are "wholly separate" from the trade negotiations.
FBI Director Christopher Wray said the cases "expose Huawei's brazen and persistent actions to exploit American companies and financial institutions, and to threaten the free and fair global marketplace".
He said he was concerned about Huawei devices in US telecommunications networks.
"That kind of access could give a foreign government the capacity to maliciously modify or steal information, conduct undetected espionage, or exert pressure or control."