Using local characters in swift names for public libraries

Question

I've made a fork of a library providing local country data for different counties.

I want to add there all countries and regions listed in ISO 3166, but there is an issue.

This standard (as wiki article) contains some country or region names using their local characters, like "Réunion" or "Åland Islands".

What would be correct swift names?

case reunion  
case alandIslands 

or

case réunion
case ålandIslands

Thank you.