US Secretary of State Mike Pompeo is flying to the UK for talks after the government decided to allow Huawei to have a role in the UK’s 5G network.
Mr Pompeo previously said the Chinese firm’s equipment posed a spying risk, adding the US “won’t be able to share information” with nations that used it.
But Culture Secretary Baroness Morgan said the decision “in no way affects the ability for the UK to share classified data” with its partners.
Mr Pompeo will also meet Boris Johnson.
The US State Department said Mr Pompeo’s visit was an opportunity to “reaffirm the special relationship following the UK’s departure from the EU and discuss ways to broaden and deepen trade ties”.
But the case of Harry Dunn is also expected to be discussed with the PM and Foreign Secretary Dominic Raab, after Washington refused the UK’s request for the extradition of Anne Sacoolas – an American diplomat’s wife suspected of causing his death by dangerous driving.
After his visit, Mr Pompeo will fly to Ukraine on Thursday.
Ahead of Tuesday’s National Security Council decision on Huawei, the US had warned that giving the firm a role in 5G could allow the Chinese government a “back door” into the telecoms network through which they could carry out espionage or cyber attacks.
But the UK said the firm will be barred from sensitive locations, such as nuclear sites and military bases and its share of the market will be capped at 35%.
Baroness Morgan also told BBC Breakfast the UK had expertise is mitigating risks when using Huawei’s technology, as it was already part of existing 4G networks – unlike in the US.
She said: “We want to see the roll-out of 5G…for the growth of our economy and productivity, but in making this decision, we have been very clear we will not compromise on national security.
“We obviously had a number of conversations with the US [who] have made their views clear. But we have got that expertise, we have had that oversight of Huawei…which gives our agencies the ability to give the assurance that having them involved in the periphery of the network does not present the security challenge I think others have worried about.”
Following the announcement, Mr Johnson spoke to President Donald Trump to explain the decision and try to allay US concerns.
A Trump administration official said the US was “disappointed” with the decision.
Mr Pompeo urged the UK to prioritise its own and its allies security interests when dealing with Huawei during his last visit to the UK in May.
The UK’s decision also faced a criticism from some senior Conservative MPs after Mr Raab made a statement about it in the Commons.
Tom Tugendhat, former chair of the Foreign Affairs Select Committee, tweeted that the government’s “statement leaves many concerns and does not close the UK’s networks to a frequently malign international actor”.
But Defence Secretary Ben Wallace downplayed such concerns, telling the BBC the UK should not be “paranoid” that the decision would lead to “Big Brother from China watching us”.
Asked about how the US might react Mr Wallace said: “I don’t know how they’ll react…they’ve made their concerns clear.
“We understand that – we respect that, we’ve given them lots of assurances that the intelligence they share and how they share it.”
‘Pervasive espionage’ claim
A series of US congressional figures called on the UK to reconsider, saying the decision could be an obstacle to a post-Brexit trade deal between the US and UK, as well as raising questions over security co-operation.
Senator Tom Cotton, a Republican member of the Senate intelligence committee, called for a “thorough review” of intelligence sharing with the UK.
“I fear London has freed itself from Brussels only to cede sovereignty to Beijing,” he said.
The decision gave China a foothold to carry out “pervasive espionage” on the UK and gave it “increased economic and political leverage”, he said.
Senator Lindsey Graham, a Republican who is one of the president’s most committed defenders, said he was “very concerned” and urged the UK to think again.
“This decision has the potential to jeopardise US-UK intelligence sharing agreements and could greatly complicate a US-UK free trade agreement,” he tweeted.