Samsung Pay launched in South Korea back in 2015, then expanded into the US, China, and more for a total of 19 official markets before today. Now, Samsung adds number 20: Mexico. You may be thinking, "didn't that already happen?" Well, apparently the appearance of the landing page last November was not the full launch.
In late November 2017, we spotted the Samsung Pay site for Mexico. There was a registration page, but you had to be accepted before getting access to Samsung Pay. That page is gone now. This might have been a way to soft-launch the service or maybe people were just registering to be notified. As of tomorrow (January 30th), you should be able to use the Samsung Pay app on your phone to set up cards immediately.
According to Samsung, you can now use Samsung Pay in Mexico with cards from banks like Banorte, Banregio, Citibanamex, HSBC, and Santander. Samsung Pay uses both NFC and MST technology, so it works almost anywhere that can swipe a card. You need a phone with the MST hardware built-in to use that feature, but all of Samsung's flagship phones for the last few years have it. A few mid-range devices like J7 Pro and A8 also work with MST.