Samsung has recently announced the Samsung Gear S2 will support the companies new mobile payment system, Samsung Pay, which is scheduled to launch in the US and South Korea later this month. The mobile payment system will be available on Samsung’s latest smartphones, like the Galaxy S6 range and the new Galaxy Note 5, but there is currently no Tizen Smartphones that have NFC built in.
Mobile payments systems are ideally suited to Smartwatches, a device that is on-hand (excuse the pun) and which you don't have to wrestle with your pocket to get out. The Gear S2 and Gears S2 Classic both come with NFC and will support Samsung Pay. Samsung have stated that Samsung Pay will be made available on the Gear S2 smartwatch some time in November.