I am in Australia and cannot access Itunes from my Ipad. I get a message stating that Itunes is not available for this country. Not a major issue as I can access most of what I want from my PC and then since.
Log off on your PC and create a new account in the US-Store, using a Gmail-Address or similar service.
Then look up any postal address in the US and enter that in your new account.
Payment option is "none".
After the next sync, you should have access from the iPad.