>>>I have spoken with an INS agent about this and he has told me that in countries where there is a low
risk of people claiming asylum and seeking refugee status they conduct pre-inspection to sort the
flights on arrival in the US. Whether or not this is true I do not know.
I always understood it to be the opposite: they check would-be immigrants from countries which more refugees/asylum seekers are expected from; reason: they want these people not even set foot on US soil, because if they do, even before they passed immigration, they can seek asylum.
The UK used to do that in Prague but stopped after massive local protests.