Immigration Site

I would appreciate any of your comments.

Im a naturalized US citizen living in US. My 16-year old child lives outside of US as a home country (Country X) citizen. Im applying for his immigration. I-130 was approved. I submitted I-864. Now I was told by NVC I must complete I-864W, as he will become a US citizen immediately upon entry under the Child Citizenship Act (CCA), we meet all the criteria.

My dilemma is that, my childs home country does not allow dual citizenship. Once he acquires US citizneship automatically, he has to give up his Country X citizenship. At this time my child is not ready to give up his home country citizenship due to his deep root in home country and little knowledge about US. Once he is in US, he wants to keep his PR status for some years. Then he will be mature enough to decide if he wants to become a US citizen later.

My question is, once he is in US with IR-2 visa, can he choose to keep his Country X citizenship? In another word, can he NOT acquire the US citizenship automatically, and just keep his Green Card status for some years?

of course , he can remain his native citizenship.

how would his country know that he has an American passport?

Thank you all for the reply.
Once my son is in US with me, he is going to travel back once a year. If he goes back with his original home country passport, the home country Border agents would ask to see his US greencard. Belive me, this sounds weird but its true.
Once my son is in US as PR, he still wants to continue the PR status. Would US INS take my sons green card away because of the Child Citizenship Act and my son acquires the US citizenship automatically? Without Green Card, my son would not be able to travel freely with his home country passport.