Donald Trump believes the King has “got a great way about him” and Liz Truss will do “very well” as Prime Minister.
The former US president praised Ms Truss for following a tax-cutting agenda.
In an interview with GB News, he said: “I cut taxes very substantially and we did much more business and she’s done that.
“And I know she’s taken some hits for it, which surprises me actually, but it could be at the end of the day you do bigger revenues, it’s going to be very interesting.
“What she did is very inverse to what some people thought. But that doesn’t mean they were right. I have a feeling she might be right.”
He said the King has “an agenda” and a “strong view on things”.
“Well, I think he’ll be different now,” Mr Trump said.
“I know him very well, quite well. And I spent a lot of time when I was over there as president with him. And with his wife (who) was absolutely lovely, by the way, and we had a good time together.
“And I, you know, so I’m a little prejudiced when I say it, but, you know, he had a strong view on things.
“Probably difficult when you’re the king you want to have 100% of the people love you like the Queen did. The Queen had – everybody loved her, right? She didn’t have that kind of an agenda.
“And yet, you know, she was a very strong woman. I got to know her too. She was a very strong woman, a great woman. I think Charles is going to do very well. I think he’s got a great way about him.”