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I am travelling from Ottawa, Canada to Munich, Germany with a Greek passport. My flight goes through Philadelphia. I travelled to the US before without a visa (Greece is in the US Visa Waiver Program) but I don't remember if I had to do some paperwork back then.
Do I need to prepare anything before I change flights in US ground, or do I just show up there with my passport?
- My passport doesn't expire until a couple of years from now.
- I have an (expired) US tourist visa, as I had travelled to the US before Greece entered in the Visa Waiver Program.