Donald Trump has warned Boris Johnson he is making a "big mistake" by backing "ridiculous" wind farms to achieve net zero.
The former US president said he still admired Mr Johnson - who he once claimed was known as "Britain Trump" - but claimed he was wrong on backing wind power.
Mr Trump unsuccessfully tried to prevent the Scottish Government from building wind turbines off the coast of Aberdeen - as he claimed it would ruin views from his golf course.
The Prime Minister has abandoned his scepticism about wind power, which he said could not "pull the skin off a rice pudding" back in 2013.
In the build up to the COP26 climate summit in Glasgow, Mr Johnson said he wanted Britain to be the Saudi Arabia of wind power in the drive to reach net zero by 2050.
But Mr Trump, in a GB News interview with ex- Brexit Party leader Nigel Farage, said the UK was destroying its landscape by permitting the turbines to be installed.
He said: "He's wrong, Boris is wrong if he's going heavy into wind.
"He's making a big mistake."
The former White House incumbent labelled wind power the "most expensive form of energy".
In comments made in Florida on Monday and due to be aired this week, Mr Trump said: "I think wind is, I think it's ridiculous."
The one-term president added: "Remember, every 10 years, you have to replace those monsters.
"And a lot of times they don't bother.
"You know what they do? They just let them rot. They kill all the birds, they are so bad."
Despite the criticism, Mr Trump - defeated by Joe Biden in last year's presidential election - said he was fond of the Prime Minister, who he suggested had become "more liberal".
"I like him. I get along with him. I've always gotten along with him," Mr Trump said.
"He's gone a little bit on the more liberal side.
"But I'll tell you with energy, I'm surprised that he would allow that to happen because you have one of the most beautiful countries in the world.
"And you're destroying it with all these wind turbines all over the place."
Downing Street refused to comment on the point but said wind power was a key part of the UK's green strategy.
The PM's spokesman said: "I haven't spoken to him about that specific point but you have seen that we believe that wind power is a vital part of what is already our energy mix.
"It's a key part of meeting our commitments."
