Trump spent longer on the phone with Piers Morgan than he did with Theresa May
According to a transcript of the call obtained by the Times, Trump asked May to "pass on his regards" to the Queen and extended a bizarrely casual invitation for her to come to the US.
He told May: "If you travel to the US, you should let me know."
The tone of the comment reportedly "raised eyebrows" among British officials: a state visit by the prime minister is a formal occasion that takes months to organise and costs millions of pounds. Senior civil servants were left "befuddled" by the comments and said they were "un-presidential," according to the Guardian.
The president-elect enjoys friendships with other British figures, including UKIP leader Nigel Farage and Piers Morgan, who is currently the US editor of Mail Online. Both claim to have spoken to him for longer periods of time than May since his election victory.
Farage, a vocal supporter of Trump, spent 50 minutes talking with Trump at Trump Tower in New York last week - and his aides believe that the new president will "run ideas" past the UKIP leader before consulting May.
Piers Morgan, meanwhile, tweeted news of a phone call between the pair on Thursday:
Morgan was a prominent cheerleader for Trump in the run-up to the election. Last week Morgan described the Republican candidate as "warm, cuddly, and delicious."
A spokesperson for the prime minister insisted that "the invitation from the president-elect was a very warm invitation to come as soon as possible."
Nonetheless, the brief call does highlight the fact that May has a task on her hand to win the close confidence of the new president-elect.
Trump owns a golf course in Aberdeenshire, Scotland, and his late mother was Scottish. He spoke of her affection for the Queen during the ten-minute call, and a told the prime minister that the UK was "a very special place for me and my country."