I always thought that USPS was strictly in the US until I ordered something from Amazon that was shipped from Hong Kong. I had no idea what kind of tracking number it was, so I asked the seller, and I was told it was shipped via USPS. The tracking number didn't work when entering it in the tracking section for USPS, though. It turns out it was shipped via USPS International. Packages shipped through USPS International can ship from countries other than the US, and they have their own tracking number system. I can't remember what I did to successfully track my package. On the USPS site, hover your mouse over "International" and paste your tracking number into the "Search or Enter a Tracking Number" field. If that doesn't work, try tracking it here: https://www.stamps.com//shipstatus/