HUAWEI
An employee works on a mobile phone production line at Huawei's factory campus in Dongguan, Guangdong province, China March 25, 2019.
(Photo: REUTERS/Tyrone Siu/File Photo)

Huawei can tap into communication lines via the equipment it sells globally -- without being detected, a US official said as Washington ramped up pressures to convince its allies to ban its Chinese maker from high-tech mobile networks.

Robert O'Brien, the US national security adviser, issued his remarks during the Atlantic Council Forum Tuesday evening after a media report quoted the official as saying Huawei has the capability to "access sensitive and personal information" in communications devices it sells and maintains around the world.

The US has long claimed that the Chinese telecoms giant has "backdoor access" to cellular phone systems it helps manufacture globally. Now, O'Brien and US President Donald Trump's other security advisers insist they have proof of this and provided information to Germany and Britain.

US officials argued that Huawei is duty-bound by the Chinese law to gather intelligence on behalf of the state's ruling Communist Party. Huawei has junked this allegation and released a statement Wednesday clarifying the telco has never and will never illegally and secretly access cellular networks.

The US has disclosed that it does not need to show evidence that Huawei can penetrate the networks, and it still is not revealing proof, although details have been shared with other countries.

US officials said they have kept information a top-secret until late last year when they shared details to its European allies.

Officials said that Huawei does not disclose information about its covert access to local clients, or the host country's security agencies.

Recently, Britain and Germany were both warned by the US that it would withhold information from the countries if they were found to be using Huawei's communication devices in their 5G networks.

However, the UK government announced in January that it would allow the Chinese telecoms firm to build components of Europe's 5G network, albeit with some limitations.

As this developed, Huawei has fired back on US accusations of spying, claiming that it does not have the capability alleged by the Americans and claimed that the Americans themselves have a long history of spying on phone networks.

In a six-paragraph statement sent to media groups, Huawei said that as evidenced by the Snowden leaks, "the United States has been illegally accessing communications networks globally, spying on countries for quite some time."

Huawei said that the report by the Washington Post this week about how the Central Intelligence Agency tapped an encryption company to eavesdrop on other nations for many years is yet an additional evidence.