US Secretary of State Mike Pompeo is expected to warn the Prime Minister when he meets her for talks in Downing Street.
The United States wants to keep the technology company out of sensitive infrastructure programmes (Picture: PA).
US Secretary of State Mike Pompeo is expected to warn Theresa May over plans to involve Chinese tech giant Huawei in the UK's 5G telecoms network when he meets the Prime Minister for talks in Downing Street.
Mr Pompeo is the first member of US President Donald Trump's administration to speak face-to-face with the PM and Foreign Secretary Jeremy Hunt since last month's National Security Council (NSC) agreed to consider Huawei's involvement.
In talks at 10 Downing Street, Mr Pompeo is also expected to step up US pressure on the UK to isolate Iran.
He made a surprise visit to Iraq immediately before his trip to London, assuring Baghdad that the US opposes other states "interfering in their country" and stands ready "to ensure that Iraq is a sovereign, independent nation".
Mr Trump last year unilaterally pulled the US out of an international nuclear deal with Iran, but the UK and other European powers have refused to follow his lead.
Mr Trump's national security adviser John Bolton said the move sent "a clear and unmistakable message to the Iranian regime that any attack on United States interest or on those of our allies will be met with unrelenting force".