Boris Johnson is understood to have cancelled plans for a spring visit to the United States amid tensions with Donald Trump over the decision to allow Chinese firm Huawei a role in the UK's 5G network.
Downing Street denied that the prime minister had been forced to delay the trip over the Huawei decision, which reportedly sent Mr Trump into a furious rage during a telephone call with Mr Johnson.
The prime minister was expected to travel to Washington at the beginning of the year for a high-profile meeting with the president as focus shifts to securing a lucrative post-Brexit trade deal with the US.
But the trip is understood to have been pushed back to June to coincide with a meeting of G7 leaders at Camp David, in Maryland.
The US president was said to be "apoplectic" with rage over Mr Johnson's refusal to ban Huawei, which Washington believes could pose a security threat due to the firm's relationship with the Chinese government. Huawei has strongly denied the allegations.
Tensions also remain over Washington's refusal to extradite the wife of a US diplomat, Anne Sacoolas, who is accused of involvement in the death of British teenager Harry Dunne.
Downing Street insisted the prime minister was focused on delivering his domestic agenda, with sources saying he had asked for foreign travel to be reduced to allow him to focus on his domestic agenda.
Using a Lord of the Rings analogy, a senior Downing Street figure told The Sun: “Levelling up the country, making the streets safe and sorting out the NHS is why the PM won the election.
“When the Eye of Sauron is off the Whitehall machine, things stop working.”
Asked if the visit had been delayed over the Huawei decision, a spokesman for the prime minister said: "The PM looks forward to visiting the US and will remain in touch with the administration.
"I will add, he is currently focused on driving through government's ambitious domestic agenda and on levelling up across the country to deliver for the people of Britain."
The spokesman said the UK "continues to have an excellent relationship with the US", when asked if the prime minister was not welcome in Washington.
Asked about what a delay meant for US-UK trade talks, a spokesman said: "Both we and the US have been clear of our intention to secure a free trade deal and work on that - as we've set out in the house a week or so ago - is ready and can start."
It comes after reports emerged that the president was livid when Mr Johnson informed him of the decision on Huawei by telephone call.
One official who was briefed on the contents of the call, which took place on 28 January, told the Financial Times that Mr Trump was “apoplectic” with rage.
Another said the call was “very difficult” and the president's tone had taken British officials aback.