Donald Trump has grown frustrated with Theresa May’s “school mistress” tone, allies of the president have told The Telegraph, as it emerged the pair will not hold formal talks at the G7 summit in Canada.

The US president is said to bristle at the Prime Minister’s approach during phone calls, with Mrs May quick to get into policy details rather than wider conversation.

One senior US diplomat said Mr Trump had expressed annoyance at Mrs May’s frequent demands, which are seen as taking advantage of the UK-US relationship.

Another long-time friend of the president revealed he had privately complained of how Mrs May calls him out in public when he is deemed to have stepped out of line.

A third figure, a former White House official who attended meetings between the pair, confirmed the frosty relationship: "No offence, but she is basically a school mistress. I’m not sure anyone gets on well with her.”

Donald Trump and Theresa May were photographed holding hands in January 2017, raising hopes they could strike up a political friendship credit: New York Times / Redux / eyevine

The comments made to this newspaper chime with a report in The Washington Post on Thursday that Mr Trump sees Mrs May as too politically correct after she rebuked him over claims that parts of London have become “no-go” areas.

Asked about Mr Trump’s reported view of her before the summit in Quebec, Mrs May said: “I just get on and make sure that I’m delivering. That’s the job of any politician.”

World leaders will gather on Friday in Charlevoix, Quebec, for a meeting of the G7 that has been overshadowed by Mr Trump’s decision to hit allies with hefty steel tariffs.

On the agenda for the two-day summit will be economic growth, the future of employment, gender equality, climate change and world peace.

Prime Minister Theresa May arrives in Quebec for the G7 leaders summit credit: AFP

However, the discussions risk being overshadowed by a growing rift between Mr Trump and leaders of countries traditionally closely aligned with America.

Mr Trump’s decision to put 25 per cent steel tariffs and 10 per cent aluminium tariffs on Canada, Mexico and the European Union have infuriated allies, as has his withdrawal from the Iran nuclear deal.

Government sources said Mr Trump was not expected to hold bi-lateral meetings with Mrs May during the trip.

The White House said in a briefing on Wednesday that Mr Trump would hold bilateral meetings with Justin Trudeau and Emmanuel Macron, the leaders of Canada and France.

However, there was no mention of Mrs May.

Gordon Brown was once infamously snubbed by Barack Obama when he turned down five requests for a bilateral meeting during a 2009 gathering of world leaders in New York.

The then-prime minister had to settle for what one aide would later call a "snatched conversation" with Mr Obama in a kitchen, causing acute embarrassment when it was later reported.

Mrs May and Mr Trump, who have very different backgrounds and characters, have struggled to develop a close political friendship over the last 18 months.

The Prime Minister became the first world leader hosted in Mr Trump’s White House in January 2017, where the pair were pictured holding hands, but officials admit they are now not especially close.

A state visit to Britain offered at that time is still yet to happen and they have clashed a number of times over Mr Trump’s tweets and policy stances.

Former aides of Mrs May have insisted that Mr Trump often expresses his love for Britain during phone calls and adopts a respectful tone. However, few claim their relationship is especially warm.

British officials hope rolling out the red carpet when Mr Trump visits Britain on July 13 for a working trip will help improve relations, with a round of golf and tea with the Queen expected to feature.

But Mrs May is not alone in failing to build a rapport with Mr Trump. Angela Merkel, the German chancellor, has a frosty relationship with the US president, who often swipes at her country’s trade policies.

Donald Trump will head to Singapore after the G7 in Canada for his summit with North Korean leader Kim Jong-un credit: Win McNamee/Getty Images

And many Western leaders have done little to hide their anger at the US president's decisions over Iran and tariffs, going public with their criticism in recent weeks.

The row over tariffs, which have seen those affected hit back with reciprocal moves, has led to one of the most troubled run-ups to a G7 meeting in years.

Mrs May said that while she has made clear to Mr Trump that the tariffs are “unjustified”, she urged the EU to ensure its response is “proportionate”.

She said: “I made my views clear of the steel and aluminium tariffs. We disagree with these, we think they are unjustified. Obviously the EU will be responding.

"We will be working with others in the EU to ensure that response is proportionate, that it is within WTO rules. I will continue to put the argument for the importance of those trade relationships around the World.”

Prime Minister Theresa May and her husband Philip are greeted as they arrive at CAF Bagotville airfield credit: Getty

Mr Macron, widely seen as having developed one of the warmest relationships with Mr Trump among world leaders, did little to hide his frustration before the gathering.

“You say the US President doesn't care at all. Maybe, but nobody is forever,” Mr Macron said, appearing to cite the fact that Mr Trump will someday leave office.

Mr Macron also made reference to the joke that the G7 has become the 'G6 plus one', saying: "Maybe the American president doesn't care about being isolated today, but we don't mind being six, if needs be.

"Because these six represent values, represent an economic market, and more than anything, represent a real force at the international level today.”

Mr Trump referred to the trade row in a tweet on Thursday night, adding he was looking forward to seeing Mr Trudeau and Mr Macron.

The US president is reportedly unhappy at having to attend the G7, coming on the eve of his historic meeting with North Korean leader Kim Jong-un in Singapore.

The US president fears being lectured to by other world leaders and would rather spend the time preparing for his talks with Kim, according to US media reports.