This is according to Samsung Electronics’ Managing Director, Park Jin-Young who revealed this during the company’s recent earnings report. According to Park, the feature will go live in the US and South Korea in the second half of the year, but as for other countries this is something that apparently Samsung is still discussing. As for smartwatch compatibility, kind of like how the Apple Watch can facilitate mobile payments, Samsung will reveal those details at a later date.
At the moment Apple Pay is still only available in the US. However there have been signs and rumors that Apple is planning to expand to markets like Europe, China, and Canada, but nothing has been officially announced yet. Assuming Samsung really does launch in both the US and South Korea in the second half of the year, they would have beaten Apple to the punch in at least one market.
Samsung Pay relies on NFC and MST technology developed by LoopPay. What this means is that essentially their feature will be compatible with nearly all of point-of-sale units in the US, so retail stores adopting the technology should be a relatively painless process.