- I have a 17-hour layover for my CEB-AUH flight via Incheon
- I am a Filipino holding an active Working/Resident visa in the United Arab Emirates valid until 2020
- I have an active US Tourist Visa valid until 2028
Officially, having a US visa allows you to exit Incheon airport during a transit, but only when you are traveling to or from the US.
Anecdotally, I have heard that Korean immigration officials have allowed transiting passengers with a US visa to leave the airport even if they are not traveling to or from the US. I would not count on this, though, as it is very likely a mistake.