The charges were levelled by the Ministry of State Security in a post on its WeChat account, according to a report in Time.

The MSS claimed the intrusions were carried out by the now disbanded Tailored Access Operations unit of the NSA.

The charges that the NSA broke into Huawei's servers are nothing new, though the dates are different from a published account.

A report in the New York Times said the NSA operation was codenamed Shotgiant and aimed to find links between Huawei and the People's Liberation Army.

It also wanted to exploit Huawei's technology so that when the company sold equipment to other countries, both US allies and enemies, the NSA could, "roam through their computer and telephone networks to conduct surveillance and, if ordered by the president, offensive cyber operations".

An NSA document was quoted as saying: “Many of our targets communicate over Huawei-produced products. We want to make sure that we know how to exploit these products", to "gain access to networks of interest” around the world.

When Bloomberg raised the MSS allegations at a Chinese Foreign Ministry press conference on Wednesday, spokeswoman Mao Ning responded: "I am not aware of the specifics. I’d refer you to competent Chinese authorities."

Mao was also asked whether the release of a new smartphone by Huawei during a recent visit to China by US Commerce Secretary Gina Raimondo was intended to embarrass the US official.

The phone was built on technology not thought possible to be manufactured in China after several rounds of American sanctions imposed on the country.

Raimondo had said she was upset about the release of the phone during her visit.

To this, Mao responded: "It’s the company’s own decision as to when to launch a new cellphone. 

"We oppose the US’s abuse of the concept of national security to hobble Chinese companies. That discriminatory and unfair practice undermines the principle of free trade and international economic and trade rules, destabilises the global industrial and supply chains and serves the interests of no one.

"The US needs to be aware that containing and suppressing China will not stop its development, but will only make China more determined and capable in pursuing self-reliance and tech innovation."

China has accused the US of interfering in its networks on just a few occasions, though accusations the other way are made frequently.

In August, the pro-government newspaper Global Times accused US intelligence agencies of interfering with earthquake data at the Wuhan Earthquake Monitoring Centre.

The same newspaper said in March 2022 that details of a tool used to control network gear around the world to steal user data had been revealed by the National Computer Virus Emergency Response Centre.

Other accusations made by Chinese sources about the US include a report by security firm Pangu Labs in February 2022 that provided details about NSA malware, known as Bvp47, that had been found in 2013.

There have been two other cases in recent years when matters relating to the US have been raised by Chinese security firms. One was in March 2020 when 360 Core Security (Qihoo Security) claimed former CIA employee Joshua Adam Schulte was the one who leaked material to WikiLeaks which the latter published under the name Vault 7.

The other was in September 2019, when researcher Qi An Xin accused the CIA of breaching Chinese aviation industry targets between 2012 and 2017.