U.S. sanctions targeting China's Huawei have had no immediate impact on its ability to supply 5G equipment to Britain, a senior company executive said on Wednesday, calling for more time to understand the full repercussions of the restrictions.

Huawei Vice President Victor Zhang said it would take months to establish the impact of U.S. measures announced in May, which aim to cripple the firm's ability to source the advanced microchips needed to make its telecoms equipment.

"These restrictions actually haven't had an impact on Huawei's capability to supply to the UK's 5G and fibre solution at this moment," Zhang told reporters on a call. "We need to talk about the long term impact, it takes time, it takes months."

Britain granted Huawei a limited role in its future 5G networks in January, but ministers have since said the U.S. sanctions could have a significant impact on its ability to securely supply crucial pieces of networking equipment.

Prime Minister Boris Johnson, who has come under pressure from the United States and lawmakers in his own party to ban Huawei over security concerns, is expected to make a decision on whether to further restrict the company by the end of the month.

Zhang said British officials should think carefully before making what he called a "critical long-term decision."

"We believe it is important to wait until all the facts and implications are known," he said. "Now is not the time to be hasty in making such a crucial decision about Huawei."

Huawei's UK Chairman John Browne told CGTN's Global Business on Wednesday that Britain is risking throwing away its long-standing relationship with China if it bans Huawei from its 5G networks as requested by the United States.

China's ambassador to UK, Liu Xiaoming, warned this week that getting rid of Huawei would send a "very bad message" to Chinese business and would damage trust.

"You cannot have a golden era if you treat China as an enemy," said Liu.

(With input from Reuters)