Trump on Wednesday called what happened "a terrible accident" and said his administration would seek to speak with the driver "and see what we can come up with." He noted that the British drive on the left side of the road, while in the United States, people drive on the right.
"The woman was driving on the wrong side of the road," Trump said. "And that can happen."
British police say the 42-year-old woman is a suspect in an Aug. 27 collision between a car and a motorcycle near RAF Croughton, a British military base in England used by the U.S. Air Force. The 19-year-old motorcyclist, Harry Dunn, was killed.
British Prime Minister Boris Johnson's office said the prime minister spoke with Trump on Wednesday and "urged the president to reconsider the U.S. position, so the individual involved can return to the U.K., cooperate with police and allow Harry's family to receive justice."
Johnson also urged the woman to return to the U.K. to face investigation.
The woman's name hasn't been officially released.
The teenager's family met with British Foreign Secretary Dominic Raab on Wednesday and said they left feeling angry and disappointed.