The family of Harry Dunn have reached a “resolution” with the teenager’s alleged killer, Anne Sacoolas, in their civil claim for damages in the US. Radd Seiger, the spokesperson for the Dunn family, said the agreement was “a real milestone” in the family’s fight for justice and they could now “put this part of the campaign behind them”. Details of the agreement have not been disclosed, but Seiger said Dunn’s parents, Charlotte Charles and Tim Dunn, would now focus their attention on the pending criminal case and the inquest into Harry’s death that would follow. “There is much work left to be done before justice for Harry can be said to be done. There will also need to be a parliamentary inquiry into this scandal in due course,” he added. The foreign secretary, Liz Truss, said it was “absolutely not” the end of the fight to get Sacoolas to return to the UK. Speaking to reporters on the train to Washington where she will meet the US president, Joe Biden, Truss said: “We continue to press for justice for Harry.” In comments made during his meeting with Boris Johnson at the White House, Biden said the case “is being worked on”. Johnson said he was “grateful” to the US president for “personally trying to move things along”. Dunn was killed in a collision while riding his motorcycle outside RAF Croughton in Northamptonshire in August 2019. It is alleged that Sacoolas struck the teenager’s motorbike while driving from the airbase, where her husband worked for a US intelligence agency. Sacoolas claimed diplomatic immunity after the crash and was able to leave the UK. In December 2019 she was charged with causing the 19-year-old’s death by dangerous driving, but she refused to return to the UK to face trial and the US government refused to grant an extradition request in January last year. This year Biden’s administration maintained that the decision was final. The Dunn family were advised that although there could be no criminal proceedings against Sacoolas in the US, they could bring a civil claim for damages against her as her diplomatic immunity was no longer valid now she was in her home country. If the case had not been resolved, Sacoolas, 44, and her husband, Jonathan, would have been compelled to give evidence under oath. Seiger told the PA news agency: “Harry’s family will never be able to move on from his loss, but they are more determined than ever to continue to move forward. It has come as some considerable relief to them that a resolution to the civil claim has been now been reached successfully between the parties and they can put this part of the campaign behind them. “It is never easy mounting a legal battle for justice abroad, let alone in the USA, but the family’s courage and determination to see this through has been incredible.” He said the family had been supported in their claim by Dominic Raab, who was foreign secretary until last week. “We have been made aware that the US government made no secret of their displeasure at the British government’s backing of Harry’s family in bringing the claim,” he said. The Dunn family’s lawyers said Sacoolas may have been distracted by her mobile phone in the moments leading up to the collision, and lawyers acting on behalf of Sacoolas have previously admitted she drove on the “wrong side of the road for 20 seconds”. They said she acted “instinctively” and had only been in the UK for three weeks. In June Raab said the path was clear for a “virtual trial or process” that could allow some “accountability, and solace and justice for the Dunn family”. A previous offer by Sacoolas to undertake community service and make a contribution to his memory was rejected by Dunn’s family.