Prime Minister Boris Johnson on Wednesday emphasised the importance of intelligence ties with the United States in Britain's decision on whether to exclude Chinese firm Huawei from building new 5G wireless networks.
Washington has been pressuring Europe, including Britain, to exclude the firm because it argues Huawei has close ties to the Chinese government and its equipment could be used to spy for Beijing.
Britain has repeatedly delayed a decision and none is expected before the general election on December 12, when Johnson's Conservatives are hoping to be returned to power.
"I don't want this country to be unnecessarily hostile to investment from overseas," Johnson told reporters after a NATO summit in Watford, north of London, which included talks with US President Donald Trump.
"On the other hand we cannot prejudice our vital national security interests, nor can we prejudice our ability to cooperate with other Five Eyes security partners.
"That will be the key criterion that informs our decision about Huawei."
The Five Eyes intelligence community comprises Australia, Britain, Canada, New Zealand and the United States.
Johnson added: "We're going to make a decision and we're going to make it based on the paramount importance of protecting our critical national infrastructure and also protecting our Five Eyes relationships."
Last week Germany said it planned to tighten rules on non-EU takeovers of its high-tech firms, following concern about acquisitions by Chinese companies.
NATO leaders agreed at the summit to ensure "the security of our communications, including 5G, recognising the need to rely on secure and resilient systems".
In response, a Huawei spokesperson said: "We're confident the UK government will continue to take an objective and evidence-based approach.
"We agree with the 'need to rely on secure and resilient systems' as outlined in the NATO Declaration -- our 5G equipment is trusted by leading telecoms operators globally and we will continue to provide our customers with innovative, secure and resilient products."