President Trump unleashed on British Prime Minister Boris Johnson over the United Kingdom’s decision to allow controversial Chinese technology firm Huawei to supply portions of its 5G wireless network.

The leaders spoke last week after the British government defied the United States in allowing Huawei to build noncore elements of the network. The U.S. has accused Huawei of having ties to China’s Communist Party and warned that equipment could be used by the Chinese state to spy on countries.