I'm an European citizen (EU Passport) and I'll be soon traveling to a Central American country.
My flight has a one-night layover in the US, so I will actually enter US soil. I have done it in the past, my ESTA is current, my passport is ok.
I will have an onward flight (the flight that will take me to Central America), but I will have no return flight (no flight that will take me back to Europe).
I've been told that the situation recently changed and I'll now be required to have a flight back to my country.
NOTE: My final destination (Central American country) does not require that I have an onward/return flight. My main concern is US immigration.