Donald Trump blasted Boris Johnson with "apoplectic" rage during a heated phone call over the UK's decision to allow Huawei into its 5G network, according to a report.
The Prime Minister defied repeated lobbying from the US to rule that the Chinese firm could play a limited role in the infrastructure.
The States had warned the move would jeopardise intelligence sharing as it raised concerns over the telecommunications company's links to the Chinese state.
Citing officials in London and Washington, the Financial Times reported that the US president had been livid with the PM in a phone call after the decision was announced last week.
One person briefed on the contents of the call described the US president as being "apoplectic" with the PM, according to the newspaper.
Downing Street did not deny the report and pointed towards a No 10 version of events after the call, saying the PM had updated Mr Trump on the decision.
The move has been a particularly thorny one for Mr Johnson, with his Brexit plans relying heavily on striking an ambitious free trade deal with the US.
"The Prime Minister underlined the importance of like-minded countries working together to diversify the market and break the dominance of a small number of companies," the statement added.
Huawei is only one of a series of issues where the two nations are at odds.
Washington has threatened to retaliate with tariffs on the British car industry, if the Government goes ahead with a planned tax on tech companies such as Google and Facebook.
The UK is also pressing for the extradition of the wife of an American intelligence official charged with causing the death of 19-year-old motorcyclist Harry Dunn.
Nevertheless, US Secretary of State Mike Pompeo said that the "special relationship" between the UK and the US is in a "fantastic place" as he visited London.