The UK said on Monday it was reviewing the rules which govern diplomatic immunity arrangements for U.S. personnel at an air force base after a man was killed when his motorbike collided with a car driven by a U.S. diplomat's wife.
Harry Dunn, 19, died in August near RAF Croughton, a base in the central English county of Northamptonshire used by the U.S. military. American Anne Sacoolas left Britain after the fatal crash.
"I have already commissioned a review of the immunity arrangements for U.S. personnel and their families at Croughton," foreign minister Dominic Raab told parliament.
"As this case has demonstrated, I do not believe the current arrangements are right and the review will look at how we can make sure that the arrangements at Croughton cannot be used in this way again."
The government had been warned by the United States that Sacoolas was going to leave Britain, Raab also said.
British Prime Minister Boris Johnson has urged President Donald Trump to reconsider a decision to let Sacoolas use diplomatic immunity to leave the country.
Trump met Dunn's parents earlier this month in Washington, saying their meeting was "sad" but "beautiful."
In a subsequent interview, the family said they felt pressure to allow the American woman to join the session.