Two iPhones, one Canadian, one US. How do I get US / Can app store?

I just got a 2nd iPhone with a Canadian plan to accompany my iPhone with a US-based plan. I spend a lot of time in each place and wanted a plan in each country.

When I synced up my new Canadian phone with my apple ID, it also put the US App Store on the phone.

Is it possible to have my US phone have US app store and Canadian phone have Canadian App store using the same ID? Or do I have to create a new Canadian Apple ID?

Thanks!