The UK's ambassador to the US has said the only country that has a "special relationship" with the United States is "probably Israel".

"My advice to my prime minister is 'I can't just put my hands on my ears and say it's special, it's going to be fine'," Sir Christian Turner told a group of students of the transatlantic relationship in February.

The remarks were first reported by the Financial Times on Tuesday, shortly before King Charles III arrived at the White House during his state visit to the US - which comes at a time of heightened tension over the Iran war.

The UK Foreign Office (FCDO) said the "private, informal comments" were "not any reflection" of the government's position.

In a leaked audio recording of Sir Christian's meeting with UK sixth-form students visiting the US, he can be heard saying: "'Special relationship' is a phrase I try not to utter because it's quite nostalgic, it's quite backwards-looking, and it has a lot of sort of baggage about it."

"I think there is probably one country that has a special relationship with the United States, and that is probably Israel," he said.

This is awkward timing for the King, who is in the US to try to bolster the UK-US "special relationship" at time when relations between Donald Trump and Prime Minister Sir Keir Starmer are at a low ebb.

In the recording,Sir Christian also said the US and the UK shared "a deep history and affinity", particularly on security and defence, and noted their economies were "very close".

"There are things we do together that no two other countries do."

He said he did not believe the UK and the US were in a "moment of rupture" but that "we're certainly at the end of an era, and the era is changing".

"We in Europe can't just rely on a US security umbrella. So the relationship will carry on, if you want, special, but I think it's going to have to be different.

"And my advice to my prime minister is 'I can't just put my hands on my ears and say it's special, it's going to be fine,' we've got to work really clearly to see what we the UK bring to the table."

It is understood that diplomats no longer use the phrase the "special relationship", a term some view as outdated.

Former foreign secretary Jack Straw told BBC Radio 4's The World Tonight programme that Sir Christian was "absolutely right" to say Israel has a special relationship with the US.

"The United States subsidises Israel's military spending, including its spending on United States armaments, and that alone makes the relationship special," Straw said.

He added that he was "uncomfortable" using the phrase "special relationship" during his tenure as foreign secretary and would like to see it "cosigned to the bin".

Speaking to BBC Newsnight, former British ambassador Lord Darroch called the leaked audio a "betrayal" and "massive breach of trust".

"He'll [Sir Christian] be kicking himself for it," he added.

In response to Sir Christian's comments on Israel, Lord Darroch said it was "hard to see anyone disagreeing with any of it" as it has been "the conversation in corridors across Westminster".

It is arguably true that Israel is currently a much closer American ally than the UK. Those two nations are currently fighting a war in Iran together - a war the UK Prime Minister has refused to get involved in.

But none of that will spare the embarrassment of these remarks being made public right in the middle of the royal visit.

In his wide-ranging remarks, Sir Christian also said it was "extraordinary" the scandal surrounding the sex offender financier Jeffrey Epstein had "not touched anybody" in the US.

He said that, by contrast, the controversy had "brought down" the former prince Andrew Mountbatten-Windsor and Sir Christian's predecessor in Washington, Lord Peter Mandelson.

Mountbatten-Windsor has repeatedly denied any wrongdoing in relation to Epstein. Lord Mandelson has apologised for maintaining a friendship with Epstein and said he only learned "the actual truth about him" after his death.

To some this will sound like criticism of the American political and justice systems, something a successful diplomat would never want to be accused of.

It also brings Jeffrey Epstein's name back into the spotlight. The King and Queen are under pressure to meet with Epstein survivors while they are in America - something they do not plan to do.

While the president is still dealing with the political fallout from the Epstein files, no one will thank the ambassador for putting Epstein's name back in the headlines.

A career diplomat, Sir Christian was appointed UK ambassador to the US in December.

The FCDO said in a statement: "These were private, informal comments made to a group of UK sixth-form students visiting the US in early February.

"They are certainly not any reflection of the UK government's position."