Accidentally changed iTunes store?

I have an iPhone 5, and I somehow changed the store to the UK. It's not on the iTunes on my computer… It's the iTunes on my iPhone. Can someone help me change it? I'm in the US, not in the UK, and I can't download any other apps until I change back. Help?

Settings > iTunes & App Store

Click your Apple ID and View Apple ID (enter password if necessary)

Then click on Country and Region and set it as United States.

Agree to the Terms and Services for that country and you're all set.