Any extradition of Andrew and Tristan Tate from the U.S. to the United Kingdom would ultimately rest with the State Department.

An American woman who fled the U.K. claiming diplomatic immunity after she was involved in a fatal traffic accident has appeared in a British court via videolink — an apparent breakthrough in the long-deadlocked case.

Sacoolas, who has acknowledged driving the car, left the UK three weeks after the collision, Northamptonshire Police say, claiming diplomatic immunity. "There is no dispute as to what happened," Sacoolas' legal representative Amy Jeffress said last month. Dunn's family now want Sacoolas to return to the UK to face the legal system, either voluntarily or through extradition. "It's difficult to overstate the extent to which the administration abused its power here by recalling the Sacoolas family back to the United States after the collision. The US State Department told CNN last month that diplomatic immunity is "rarely waived."

Harry Dunn, 19, died in the accident while riding his motorbike, according to a statement from his(CNN) - The diplomatic immunity of the wife of an American diplomat who is the suspect in a fatal traffic collision that killed a British teenager "is no longer pertinent," the UK Foreign Secretary said Sunday. "The US have now informed us that they too consider that immunity is no longer pertinent," UK Foreign Secretary Dominic Raab said in a letter written to Dunn's family. The Foreign Secretary continued that "the UK government's position is that immunity, and therefore any question of waiver, is no longer relevant in Mrs. Sacoolas' case, because she has returned home," he wrote. This could provide an opportunity for UK authorities to commence legal action with a view to extraditing Sacoolas back to the UK to face prosecution. "The Foreign Secretary has been working with his American counterparts and has been in touch with the US administration on this.