While I disagree with the parent on helping US citizens first, I don't think it's generally wrong to put your own people first if you have to choose. That doesn't mean that other people are worth less, it simply means that, if you can choose one or the other, it's not generally reprehensible to choose people close to you, at least in my opinion.
Imagine, for example, a natural disaster strikes and you're forced to either save the live of your own child or a complete stranger. Anyone would choose his own child (assuming exactly similar circumstances). That does not mean the other childs live is worth less. It's exactly the same thing if it's about people in your country or a foreign one - of course, your relation is less intense, but it still holds.
Other comments explain why you'd choose contrary to this in this case, but I don't think we should assume bad faith in the parent.
