Pressure is mounting on British Prime Minister Boris Johnson ahead of his decision on whether to use Huawei equipment in future 5G mobile networks.
Reports said U.S. government officials presented the British government with new evidence on Monday
about the risks of including the Chinese firm's technology, branding it "madness".
Speaking on Tuesday the PM insisted he wouldn't undermine national security
but said critics of Huawei would need to suggest another option.
(SOUNDBITE) BRITISH PRIME MINISTER, BORIS JOHNSON, SAYING:
"The British public deserve to have access to the best possible technology. I've talked about infrastructure and technology. We want to put in gigabit broadband for everybody. Now, if people oppose one brand or another, then they have to tell us which is the, what's the alternative? Right? On the other hand, let's be clear. I don't want, as the UK prime minister, to put in any infrastructure that is going to prejudice our national security or our ability to cooperate with five eyes intelligence partners"
Officials from both countries and the telecoms industry met on Monday ahead of Britain's decision, expected later this month.
And the U.S. has been piling on the pressure.
The British defense minister told the Sunday Times newspaper that President Trump and his advisers have threatened to cut off some intelligence to the UK if the National Security Council gives Huawei a green light.
Huawei, the world's largest maker of mobile networking equipment, has repeatedly denied that its equipment could be used for spying.