Purchasing a gift card in a non-US country

I need to send gift cards to our friends in several non-US countries; Europe, Japan, Sweden, etc. I have gotten through the correct site for each country and had no problems until I need to fill out payment information. I'm only given that country as an option; Belgium, Japan, Sweden, etc. The US is not an option.

How do I enter my billing address so I can purchase the Apple gift cards in their countries so they can use them?

Thanks!