There will be “no haggle” over Harry Dunn’s death and investigations of Prince Andrew’s Jeffery Epstein connections, the government says.
Foreign Secretary Dominic Raab responded after US Secretary of State Mike Pompeo was asked if there was a “deal to be done” regarding the cases.
Mr Raab stressed the extradition treaty with the US is “rules-based” and there would be no “barter” over the cases.
Mr Dunn’s family is treating the developments “with caution”.
The 19-year-old died after a crash in Northamptonshire in August, before suspect Anne Sacoolas left for the US, citing diplomatic immunity over the case.
In his response to the question, Mr Pompeo said Mr Dunn’s case and the investigation into allegations about Prince Andrew would be “resolved on their merits”.
At an event in London alongside Mr Raab, Mr Pompeo was asked if there was “a deal to be done” over Prince Andrew and Mrs Sacoolas.
The secretary of state replied: “Yeah, I can answer that. I am confident each of these cases will be resolved on their relative merits.”
Mr Raab added: “There is no barter, it’s a rules-based approach. That’s what the treaty does.
“We both see that the extradition treaty serves both sides. And we want to make it work. So, that’s the approach.
“There is no haggle and no-one’s raised Prince Andrew. Frankly, no-one has ever raised that with me.”
Mr Pompeo countered: “Yes, now they have.”
The developments come after US attorney Geoffrey Berman said on Monday that Prince Andrew had provided “zero co-operation” to an inquiry into late sex offender Jeffrey Epstein.
Prosecutors and the FBI have contacted his lawyers but have received no reply according to the lead investigator, Mr Berman.
Prince Andrew says he did not see, or suspect, any suspicious behaviour when visiting the homes of Mr Epstein.
Buckingham Palace said the prince’s legal team was dealing with the issue.
Mr Dunn died after being fatally injured outside RAF Croughton, Northamptonshire, where Mrs Sacoolas’s husband Jonathan worked as an intelligence officer.
She was charged with causing death by dangerous driving last month.
Radd Seiger, spokesman for Mr Dunn’s family, has noted that despite his clients’ caution, “the secretary of state is no longer saying [Mrs Sacoolas] will not return”.
“We treat these words with caution but it is clear that Mr Raab has followed through on his promise to the family that he would make it clear to the secretary of state that he will not accept anything less than Anne Sacoolas’ return,” he said.
Mr Dunn’s mother Charlotte Charles said the family has stressed “right from the outset that Anne Sacoolas must face the legal system here”.
“There is no other way and no-one is above the law, diplomat or not, as the Vienna Convention makes clear,” she added.