US Secretary of State Mike Pompeo is expected to warn Theresa May about her plans to involve Chinese tech giant Huawei in the UK's 5G telecommunications network when he meets the prime minister in Downing Street.

Mr Pompeo is the first member of President Donald Trump's administration to speak face-to-face with the prime minister and Foreign Secretary Jeremy Hunt since the National Security Council met last month and agreed to consider Huawei's involvement.
Washington is urging allies to keep Huawei out of sensitive infrastructure programs, citing fears that the company could provide a pathway for China's communist regime to spy on the West.
Mrs May gave the green light to the company that offered to work on “non-core” aspects of the high-tech 5G network at the NSC meeting, overriding concerns from ministers such as Gavin Williamson, who later sacked a cabinet secretary on suspicion of leaking details of the discussions.
Mr. Pompeo has previously warned that the US will not “work with” countries that adopt Huawei systems. “We have made it clear that if the risk to the United States exceeds the threshold, we simply will not be able to share that information anymore,” he said last month.
In talks at 10 Downing Street, Mr Pompeo is also expected to step up US on the UK to isolate Iran.

He made a surprise visit to Iraq just before his trip to London, assuring Baghdad that the US opposes other states “intervening in their country” and is ready “to ensure that Iraq is a sovereign and independent nation.”.
Mr Trump unilaterally withdrew the US from an international nuclear deal with Iran, but the UK and other European powers refused to follow his line.
Trump administration adviser John Bolton said the move sent “a clear and unequivocal message to the Iranian regime that any attack on United States interests or the interests of our allies will be met with relentless force.”.
