New York JFK connection for two separately purchased international flights

Question

Here is my itinerary, followed by my question:

X (a European city) --> New York, JFK
New York, JFK --> Y (a South American city)

Do I need to pass through the passport control at JFK if I purchase those two flights separately?

Answer 1

There are no transit areas in US airports. Pathways through US immigration are the same regardless of whether you are leaving the airport immediately afterwards, taking a domestic connection, or taking an international connection. Thus, you need to have appropriate documentation to enter the US for whatever is your intended purpose (in your case, transit).