British cybersecurity inspectors have found significant technical issues in Chinese telecom supplier Huawei's software that they say pose risks for the country's telecom companies.
The annual report Thursday said there is only "limited assurance" that long-term national security risks from Huawei's involvement in critical British telecom networks can be adequately managed.
The report adds pressure on Huawei, which is at the center of a geopolitical battle between the U.S. and China.
The U.S. government wants its European allies to ban the company from next-generation mobile networks set to roll out in coming years over fears Huawei gear could be used for cyberespionage.
The report noted that Britain's cybersecurity authorities did not believe the defects were a result of "Chinese state interference."