Washington has been pressing European allies hard to ban Huawei, one of the world's largest tech firms, from next-generation mobile data networks, saying it is a security risk.

A day after Huawei was hit with fresh criminal charges in the US, Secretary of State Mike Pompeo told the Munich Security Conference the company was a "Trojan horse for Chinese intelligence".

US Secretary of Defense Mark Esper said Huawei was the "poster child" for China's "nefarious strategy" to infiltrate and dominate crucial western infrastructure.

"If we don't understand the threat and we don't do something about it, at the end of the day it could compromise what is the most successful military alliance in history -- NATO," Esper said in Munich.

Key US allies in Europe, notably Britain and France, have said they will not ban Huawei from building 5G networks -- that will permit near-instantaneous data transfers -- but will impose restrictions.

Publicly the US has been restrained in its response to London's decision, but President Donald Trump was reportedly furious.

A US indictment on Friday laid fresh criminal charges against Huawei related to theft of intellectual property, adding to earlier allegations the company stole trade secrets from American carrier T-mobile.

While these issues anger the Trump administration, it is Huawei's potential to undermine strategic Western communications that causes the most worry.

"Reliance on Chinese 5G vendors could render our partners' critical systems vulnerable to disruption, manipulation and espionage," Esper said.

"It could also jeopardise our communications and intelligence sharing capabilities and by extension, it could jeopardise our alliances."

Washington has sanctions in place aimed at blocking Huawei from getting any US telecom equipment contracts and prevent the transfer of technology to the Chinese firm.

Huawei vehemently denies the US allegations and Beijing has characterised the company's treatment as "economic bullying".