The two leaders disagreed over the US President's decision to share racist tweets online
The US ambassador to the UK has insisted Donald Trump "admires and respects" Theresa May, despite their clash of opinion this week.
Billionaire Woody Johnson, who was appointed America's top diplomat in London earlier this year, claimed the President and Mrs May have a "very, very good relationship."
The British Prime Minister branded the US President "wrong" after he shared tweets from the far-right Britain First party this week, which also prompted an unprecedented wave of criticism from MPs.
Escalating the row, Mr Trump hit back at Mrs May, telling her "don't focus on me."
But, despite the high-profile spat between the two leaders, Mr Johnson expressed confidence there remains "100%" trust within the US-UK relationship.
Mr Johnson, the owner of American Football team the New York Jets, told Bloomberg: "The Prime Minister was one of the first, the first, visitor to the US after the inauguration of the President.
"The President and Prime Minister have a very, very good relationship.
"I know the President admires and respects the Prime Minister greatly.
"If I look down the road, my job and the President's job is to protect Americans and he's doing that the best he can.
"Are you going to have little stumbles along the road? Absolutely. You're going to have things that happen."
Mr Johnson also described Mr Trump as "excited" to come to Britain, despite politicians from all parties demanding the offer of a state visit for the US President is withdrawn following his actions this week.
Downing Street has repeatedly insisted the invitation of a state visit for Mr Trump still stands and has been accepted, although no details are available yet.
Number 10 would not comment on reports Mr Trump could visit Britain on a working visit, rather than a state visit, to open the new US embassy building as early as February next year.
Britain First's leader Paul Golding has boasted of a surge in support for his anti-Islam group since Mr Trump's endorsement of his deputy Jayda Fransen's tweets, including "hundreds" of new membership applications.