“We look forward to working with the U.K. on a way forward that results in the exclusion of untrusted vendor components from 5G networks,” the official said. “We continue to urge all countries to carefully assess the long-term national security and economic impacts of allowing untrusted vendors access to important 5G network infrastructure.”

Huawei has long denied that it is beholden to the Chinese government.

“Huawei is reassured by the U.K. government’s confirmation that we can continue working with our customers to keep the 5G rollout on track,” Victor Zhang, Huawei’s vice president, said in a statement. “This evidence-based decision will result in a more advanced, more secure and more cost-effective telecoms infrastructure that is fit for the future.”

The crown jewel of China’s tech sector, Huawei is the largest provider of equipment to build systems based on fifth-generation wireless technology, known as 5G. That technology is seen as essential infrastructure in an increasingly digitized global economy. The networks will provide substantially faster download speeds, as well as new commercial applications in industries such as transportation, manufacturing and health care.

Huawei’s prominence has made it a target of the United States. Meng Wanzhou, Huawei’s chief financial officer and the daughter of the company’s founder, is fighting an extradition order in Canada stemming from an American indictment on fraud charges.

The Trump administration’s global effort against Huawei has had some success. In 2018, Australia imposed a ban on Huawei gear, and Japan put restrictions on purchasing Huawei equipment for government use.

But in Europe, the White House has had more difficulty. The European Union has warned of national security risks related to 5G, but it has not called out China or Huawei by name or recommended an outright ban. In France, the government said it did not believe a ban was necessary. Chancellor Angela Merkel of Germany has shared similar views, though a final decision has not been made, and some in the government are calling for a harder line.

Perhaps no country was lobbied by the United States and China as hard as Britain, delaying the country’s decision-making about building its new 5G network. President Trump, Secretary of State Mike Pompeo and Treasury Secretary Steven Mnuchin have all warned Britain in recent weeks. An American delegation visited London this month to make a last-minute case against Huawei. Mr. Pompeo is scheduled to visit Britain this week.