SIR Keir Starmer raised the King’s upcoming state visit to the US in a bid to cool tensions with Donald Trump.

The Sun understands the leaders’ Sunday phone call was “not a rosy affair” following their public spat over .

UK Prime Minister Keir Starmer handing an invitation to US President Donald Trump at the White House.Sir Keir Starmer ha tried to charm the President by bringing up King Charles several times King Charles III and Queen Camilla visiting Dante's Tomb.King Charles III and Queen CamillaCredit: PA

The President has been rebuking the PM over his initial refusal to let American pilots use British air bases to strike Tehran.

An official familiar with the discussion – the first since their extraordinary falling out – revealed it was a testy exchange.

Mr Trump was said to be unmoved by Sir Keir’s attempts to explain his controversial decision to first withhold support.

Sir Keir then tried to charm the President by bringing up Charles’ scheduled trip to DC later this year.

The King and Queen are expected to travel to Washington at the end of April for a three-day visit timed to coincide with America’s 250th anniversary celebrations.

The trip is seen by diplomats as a chance to reinforce the historic ties between the two countries.

It is the second time the PM has deployed the King to love-bomb his royalist counterpart, having given him a personal letter in the last year.

But some Labour and Lib Dem MPs have urged the Government to cancel the trip in protest at Mr Trump’s attacks on Britain.

Asked whether the King’s visit to the US would go ahead as planned, Sir Keir’s official spokesman said: “I think on this, I would just say that no state visit has been confirmed yet. It’s not something I want to get drawn on .”

A readout of the call on Sunday said the two leaders discussed cooperation in the Middle East and agreed to stay in touch.

The PM had refused permission for American planes to strike Iran from bases including Fairford and the joint US-UK base on Diego Garcia in the Indian Ocean.

He later relented and allowed US missions for “specific and limited defensive purposes”.

But the delay sparked fury in Washington and multiple public dressing-downs from the US President.

Mr Trump said he was “very disappointed” in Sir Keir and mocked him as “not Winston Churchill”.

He also sneered at Britain’s offer to send military support after reports the Royal Navy could deploy an aircraft carrier, saying the US did not need allies who “join wars after we’ve already won”.