okay, I meant his mannerisms and quirky joking attitude during interviews are American. Actually, his accent is far less than a UK person, Aussie, or South African and he doesn't sound like an eastern European like Doncic, Jokic, or Djokovic.
Brits and Americans love Fed more than their own star players because he's kind of a suave James Bond of tennis and says the right things plus he'll shed some tears quite easy. Bring a tissue box with you if you interview the guy. I heard a few minutes of his "last 12 days" documentary and he sounded like he was smoking or had no sleep. Maybe that's the Euro sounding part you mentioned.