The Galaxy S6 and its curved-edges variant are critical for Samsung's plans to reverse plunging smartphone revenues that led to its first annual earnings fall in three years in 2014.
The new phones have been well-received for the revamped design and various technological improvements, prompting some brokerages to increase shipments forecasts for Samsung smartphones this year. They will start selling in 20 countries on April 10.
Earlier this week Samsung revealed that pre-orders for the device were already through the roof, suggesting that it was clawing back ground from the super-bendy out-of-date iPhone.