Does somebody know any native american english teacher who can serve as a tutor for my 13 years son..?

My 13 years son has a medium English background and is currently attending the British school but our wish is, to enroll him next year in the American School of Doha (ASD), where his sister is actually attending (in order to have both of them in the same school).

Unfortunately, he has been struggling with the language so far and needs some help to improve his English skills. In addition to this, we want him to be prepared for next year assessment at ASD. That's why I'm looking for some Native American spoken English teacher to do so in partial time.

I will appreciate if somebody meets this criterion and wants to help my son to fully achieve this challenge.

Thanks.