Financing an iPhone in Canada, then traveling abroad

I am going to finance my iPhone in canada through Apple, however on the website, it is only giving me options to finance through carriers. my question is the following:

if i finance my phone from the Apple website and choose a carrier, lets say Verizon, and then travel to a country that doesnt have that carrier, am i able to connect to a local carrier or will my phone be locked to Verizon only?