Apple Intelligence is available worldwide (excluding the EU and China) thanks to the recent release of iOS 18.1. And that's true even if you're not in the U.S. if you're willing to make a few tweaks in your iPhone options menu.
Currently, Apple Intelligence only supports English US, meaning to get access you'll need to change the region in your phone. While this does involve a bit of menu navigating it's pretty easy. However, it's worth noting that this will change you're time and date format, so you'll need to change those back.
