Are you currently physically in the US ? If you aren't then you cannot use the US store - you have to be in a country to use its store.
You can make a difference in the Apple Support Community!
When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.
When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.