Although it is available outside of the U.S., Siri's availability on the Apple TV is still fairly limited compared to the iPhone and iPad, where it's available in about 36 countries. On the Apple TV, that's limited to only 13, and it was even less than that a few years ago. The difference seems to be due to challenges in reliably looking up things like movies and TV shows in other languages and dialects — those 13 countries where it is available only cover 8 languages (English, French, Spanish, German, Portuguese, Dutch, Japanese, Norwegian, and Swedish), but even then there are some surprising omissions like New Zealand and, perhaps ironically, Portugal (although it doesn't get Siri at all anyway).