chips in fish and chips are cut potatoes. French fries are thinly-cut chips. You don't have french fries as a part of fish and chips, because then that would be fish and french fries.
Maybe that is the distinction they are making. Or do Americans call any thickness of chips "french fries"?
If that's the case then I have no idea.
In the US thick "chips" (in the British sense) can be called potato wedges or steak fries. Alternatively one could also just call them french fries.