Video report by ITV News Correspondent Neil Connery
Donald Trump has said Prime Minister Boris Johnson asked him to set up a meeting between Harry Dunn's family and the suspect in the case of his crash death.
However, the US President said the teenager's parents "were not ready", despite him thinking that they were, to meet Anne Sacoolas, after Mr Trump offered to bring her into the room during a meeting.
Following their meeting with Mr Trump on Tuesday evening, Charlotte Charles, the mother of Mr Dunn, branded the President's attempt to organise the meeting as "not appropriate".
Mr Trump described his meeting with Ms Charles and Tim Dunn as "beautiful but sad" and said he believed Ms Sacoolas had been on the wrong side of the road before the crash that left the 19-year-old dead.
Ms Sacoolas, the wife of an intelligence officer, is said to be covered by diplomatic immunity, though that protection is now in dispute.
In a statement issued on Wednesday, Ms Sacoolas said she was "disappointed" that she was not able to meet Mr Dunn's family.
A statement issued by her lawyer Amy Jeffress said: "We are trying to handle the matter privately and look forward to hearing from the family or their representatives.
"Anne accepted the invitation to the White House with the hope that the family would meet and was disappointed."
Describing Mr Dunn's parents as "very nice but desperately sad", the US President said they had a "very good meeting", and that Mr Johnson had asked him if he could arrange a meeting between Ms Sacoolas and the teenager's family.
He added that he believed the crash happened because Ms Sacoolas was on the wrong side of the road outside RAF Croughton in Northamptonshire.
"You go to Europe and the roads are opposite and it's very tough, if you're from the United States, you do make that decision to make a right turn, where you're supposed to make a left turn and the roads are opposite," the President said.
"She said that's what happened and that's what happens to a lot of people by the way," he added.
He continued: "She was in the room right out there, we met out here, this area, and I offered to bring the person in question and they weren't ready for it."
"I spoke to Boris, he asked me if I'd do that, I did that and unfortunately they wanted to meet with her but unfortunately when we had everyone together they decided not to meet, perhaps, they had lawyers involved," Mr Trump said.
Ms Charles told ITV News that their family had been asked three times to meet Ms Sacoolas at the White House.
She told ITV News Correspondent Neil Connery: "We hadn't long been in the room and then the bombshell was dropped that Anne Sacoolas was in the building as well so I think that they were just hoping, because they had mentioned it three times during our visit there, they were hoping for us to cave in."
The US Security Advisor had a clear message for Dunn's family from the start of the meeting - that Ms Sacoolas would not be travelling to the UK.
Harry's mother Charlotte told ITV News that she had asked the US president: "Just please do the right thing, just please do what you can."
While Harry’s father Mr Dunn said of turning down the chance to meet Mrs Sacoolas at the White House: “We weren’t ready to meet her, it would have been too rushed.
But he added that the meeting “didn’t feel like a stunt – they didn’t try and force it onto us”.
However the teenager’s parents said they are no “further along” after being told Ms Sacoolas would not return to the UK.
Speaking after the meeting on Tuesday, the family's spokesperson Radd Seiger said: "It was the President's intention for Harry's family to meet Mrs Sacoolas in the Oval Office in front of several photographers in what was obviously designed to be a press call.
"Harry's parents remain committed to pursuing a solution to the dispute and need one to happen quickly for the sake of their health.
"Harry's parents declined any such meeting."
Continuing his comments on the Justice4Harry GoFundMe page, Mr Seiger said: "It struck us that this meeting was hastily arranged by nincompoops on the run.
"The family remain open to the possibility of meeting Mrs Sacoolas one day in the future but in a neutral and appropriately controlled environment."