Samsung has unveiled two new flagship smartphones, the Galaxy S7 and S7 Edge.

The smartphones will come with an "always on" display, which can be used to constantly show the time, while the camera in both devices has also been reworked to provide better photos in low light.

The all-metal design that was introduced on last year's S6 continues, with the Edge remaining the only phone with a curved screen on both sides of the device.

The Korean technology giant has also reintroduced waterproofing and expandable storage through a space next to the SIM for an SD card.

A 360-degree camera, called the Gear 360, was also introduced and will enable users to film and take pictures up to 360 degrees, and post the results on Facebook and YouTube, both of which support the technology.

The unveiling came amid a press conference which Samsung delivered via virtual reality, placing a VR headset on every seat in the hall for those in attendance.

The curved screen that appears on the S7 Edge was first introduced on the S6 last year, and has proved popular with consumers and industry experts.

The 5.1in screen on the new Edge also has an expanded side menu, meaning two rows of apps can now be shown, and third party apps can now use the space to show images and news stories, Samsung said.

Samsung added that battery life on the new devices has also improved, and that both fast charging and wireless charging have improved too.

Samsung confirmed the S7 and S7 Edge will go on sale on March 11, and that customers who pre-order in the US and Europe will receive a Gear VR headset for free.

Facebook founder Mark Zuckerberg also made an appearance at the event to discuss virtual reality and 360-degree video, calling the platform "the best social experience".

Facebook owns VR firm Oculus, which partnered with Samsung to create the Gear VR headset.

Mr Zuckerberg added that he hoped to film his daughter's first steps using 360-degree video.