The Foreign Office said on Tuesday it had begun to put into effect the recommendations from the Harry Dunn review, with three already completed and nine more still in progress.

The department said new guidance was now in place for handling serious incidents involving foreign officials, including how government departments should respond and how families should be supported. It also said US personnel assigned to the UK must now receive a briefing on UK driving conditions and road safety, and must pass the UK driving theory test. Updated legal guidance and new training requirements for US personnel were already under way, and the Foreign Secretary is expected to confirm later this year that all of the recommendations have been completed.

Dame Anne Owers published the review in December after examining what the Foreign Office did between 27 August 2019 and the end of that year. Her report said the department failed to treat the case as a crisis and withheld information from Harry Dunn's family after he died. Dunn, 19, was killed outside RAF Croughton in Northamptonshire in 2019 when Anne Sacoolas, a US State Department employee who had diplomatic immunity at the time, drove on the wrong side of the road and hit him.

The case has remained a test of how the UK handles disputes involving foreign officials and the families left behind. The review said the then foreign secretary was not told the family had left the UK until the following day, underscoring how much of the department's response depended on decisions made after the loss had already become public and the family was already seeking answers.

Sacoolas later pleaded guilty in 2022 to causing death by careless driving and received an eight-month suspended jail term. The new steps now under way suggest the Foreign, Commonwealth And Development Office is trying to close the gaps the review identified before ministers say the work is finished.