My ex wife has custody in Trinidad of my son he is an American citizen and I am also. she took my son and moved to Trinidad my son has been the for the past six yrs. We had a verbal agreement that when he was old enough to fly back and forth he will move her and she will return to the states shortly after. then she losses her green card now I have my son and I want him her and she tell me when I send him back I will never see him again. What steps can I take to have my son here legally.