You need AGC denominated in USD to work in any of Amazon's Europe website?
An amazon.es gift card will probably won't work on Amazon.fr for exmaple so he must mention the country. From what I understood, he probably meant that he should be able to redeem it even If he is not from the U.S . If that's the case then I can confirm that I can redeem Amazon.com gift cards even though I'm from Algeria.