When entering stops on a route in a region other than North America, worldwide country abbreviations can be entered using either FIPS 2-character, ISO 2-character, ISO 3-character, GENC 2-character or GENC 3-character codes. FIPS codes are accepted by default. (PC*MILER Worldwide or DTOD Data must be licensed and installed.) 

In Application Settings > Worldwide, you can change the country code format by making a new selection from the drop-down menu.