Phil Neville told the Football Association (FA) that the chance to work as Inter Miami's manager was "too big an opportunity to turn down".
The former Manchester United defender left his role as head coach of England's women's national team on Monday to join the MLS club, after just less than three years in charge.
Neville was set to take charge of Great Britain's women's football team at this summer's Olympics in Tokyo too, a role he had expressed his desire for for many months.
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But with his contract with the FA to have expired after that event, when current Netherlands boss Sarina Wiegman would then take over the Lionesses, he told his employers that a role with Inter Miami was something he couldn't refuse.