LONDON — Vodafone says any move by Britain to bar equipment made by China's Huawei from all parts of new 5G networks would cost it hundreds of millions of pounds and “very significantly” slow down the deployment of the new technology.

The US asked allies not to use Huawei's technology because it could be a vehicle for Chinese spy operations, an accusation denied by the company.

Vodafone, the British telecommunications conglomerate, said last month it had paused the use of Huawei components in its core networks in Europe until governments had assessed the risks.

The group's UK chief technology officer Scott Petty said Huawei radio equipment was used in nearly a third of the company's 18,000 UK base stations — a part of the network it gauged to be very low risk. It would also be part of the foundation for 5G technology.

Vodafone said it would launch 5G in 19 towns and cities across Britain in 2019, adding 12 more locations to the seven cities that are already live or are soon to be live under its UK-wide trial.

“If we were forced to remove Huawei from the network, we would need to go to the 32%  of base stations that are currently using Huawei for radio and replace all of those with somebody else's technology and then deploy 5G on top of that,” Petty said. “The cost of doing that runs into the hundreds of millions and would dramatically affect our 5G business case; we would have to slow down the deployment of 5G very significantly.”

Operators should be able to use Huawei's radio technology on its masts even if they could not use the company's kit in the more critical transport network and core network, he said. Vodafone UK decided against using Chinese technology in the higher risk parts of its network more than five years ago, he added.

The British government is reviewing the telecoms supply chain and is due to report in the coming months.

The head of Britain's National Cyber Security Centre said last month that the country was able to manage the security risks of using Huawei's equipment and it had not seen any evidence of malicious activity by the company.