DONALD Trump raged at Boris Johnson in a furious phone call over the decision to let Huawei build Britains 5G network.
The long-awaited decision giving the go-ahead to the Chinese telecoms giant against US advice was taken by the PM and his National Security Council last week.
The FT reported the US President made his fury over the decision known to the Prime Minister spoke in a heated phone call.
Sources said Mr Trump was apoleptic with the PM, and the conversation was very difficult.
It is claimed British officials were shocked by the conversation, and could not believe the president’s language towards Mr Johnson.
A government source said: These calls can get overheated at times.
US vice-president Mike Pence later confirmed the Trump administration had made its disappointment very clear.
A summary of the call released by the White House said: Today, President Donald J Trump spoke with Prime Minister Boris Johnson of the United Kingdom.
The two leaders discussed critical regional and bilateral issues, including telecommunications security.
UK-US relations expert Thomas Wright told the FT the call showed Mr Trump had taken the issue personally.
He said: To me the significance of the phone call is that it shows that Trump is very engaged and very upset and that this is not going to blow over and it will have implications if not on Five Eyes then on trade talks.
Downing Street had earlier defended the decision, saying Britains economy would have suffered a serious hit if Huawei had been locked out completely.
The rollout of 5G as well as faster full-fibre broadband would be delayed by two to three years and tens of billions of pounds would have been stripped out of the economy.
The PM also answered a plea by intelligence chiefs to boost Britains telecoms industry to make sure it never has to rely on Chinas again.