Try figuring out the reason why they're unavailable in other countries. Coca-Cola's Pibb Xtra. Instead of Pibb Xtra, Coca-Cola sells Dr Pepper in various countries due to a licencing agreement with Keurig Dr Pepper. Pepsi's Starry. Instead of Starry, Pepsi sells 7Up in various countries also due to a licencing agreement with Keurig Dr Pepper.
By twice, I mean the first attempt was Coca-Cola BlāK, which went on sale in 2006 before being discontinued two years later and the second attempt was Coca-Cola with Coffee, which went on sale in 2017 and continues to be sold to this day.