Donald Trump has backed Rishi Sunak’s decision to delay a series of measures aimed at curbing emissions.

The Prime Minister announced plans including a five-year delay in banning petrol and diesel cars and made changes to the shift away from gas boilers in an effort to spare hard-pressed households from the cost of green commitments.

Former US president Mr Trump – who has railed against climate measures in his country – said: “I always knew Sunak was smart.”

On his social media platform Truth Social, Mr Trump said: “Prime Minsiter Sunak of the United Kingdom has very substantially rolled back the ridiculous ‘climate mandates’ that the United States is pushing on everyone, especially itself.

“I always knew Sunak was smart, that he wasn’t going to destroy and bankrupt his nation for fake climate alarmists that don’t have a clue.”

Mr Sunak has maintained the UK’s commitment to reach net zero greenhouse gas emissions by 2050, despite the changes to the way measures would be introduced.

Cabinet minister Grant Shapps told the BBC: “We have already exceeded all of our carbon budgets. We have the leading position in the G7 in terms of the amount of carbon that we’ve reduced.”

And he insisted that 2035 was “always the end date for the sale of petrol and diesel cars” because hybrid-powered vehicles were allowed to be on sale to that date.

The original plan had meant new cars powered only by petrol or diesel would have been banned by 2030, but that has now slipped to 2035.

The Defence Secretary insisted the UK was still on course to meet its commitments despite the changes on cars and boilers: “We think that we can both meet our 2050 commitments and give families a bit of a break and enable them to change their boilers as the time comes, rather than force a sort of pace which is unrealistic.”