US intelligence officials have warned that smartphones and other networked hardware from Chinese companies, such as Huawei and ZTE, could be used "to conduct undetected espionage".
The warning comes from six intelligence officials - including the heads of the CIA, FBI and National Security Agency (NSA) - appearing before the Senate Intelligence Committee.
FBI director Christopher Wray testified: "We're deeply concerned about the risks of allowing any company or entity that is beholden to foreign governments that don't share our values to gain positions of power inside our telecommunications networks."
It provides the capacity to conduct undetected espionage
"That provides the capacity to exert pressure or control over our telecommunications infrastructure. It provides the capacity to maliciously modify or steal information. And it provides the capacity to conduct undetected espionage."
Michael Rogers, the NSA's director, added: "This is a challenge I think that is only going to increase, not lessen over time for us. You need to look long and hard at companies like this."
Huawei, which recently saw AT&T and Verizon back out of deals to provide its smartphones to customers following pressure from the US government, said in response: "Huawei is aware of a range of US government activities seemingly aimed at inhibiting Huawei's business in the US market.
"Huawei is trusted by governments and customers in 170 countries worldwide and poses no greater cyber security risk than any ICT vendor, sharing as we do common global supply chains and production capabilities."
Despite these setbacks, Huawei is still selling an unlocked version of its flagship Mate 10 Pro in the US. However, the firm has taken desperate measures in order to do so, having reportedly pushed users to write fake reviews for the smartphone.
News of this latest challenge by the US government comes just weeks after the Trump administration revealed that it is tentatively considering plans to build its own 5G network in order to counter various perceived security threats from Chinese firms.
Huawei is trusted by governments and customers in 170 countries worldwide and poses no greater cyber security risk than any ICT vendor
Speaking to Reuters, an unnamed official said the US government wants to "build a network so the Chinese can't listen to your calls".
"We have to have a secure network that doesn't allow bad actors to get in. We also have to ensure the Chinese don't take over the market and put every non-5G network out of business," he added.
In the UK, though, Huawei is a key supplier to BT, forming part of the backbone of the UK's communications infrastructure. However, its equipment is vetted first by GCHQ, which claims that it has found nothing amiss in the hardware.
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