I think Trump was being obtuse with Turnbull because he wants something in return, he is trying to get him to offer something, he just can't ask for anything himself. Otherwise he would just have had to ask how many do they have to take in and would have said Ok, zero. Instead he is arguing as if he is expecting Turbull to offer something but he never does.
I don't really see that. I just see Trump being shallow and self-centered in this. There were several spots where that door was opened by Turnbull and Trump never took it, if that was his real angle.