A tear-jerking video of an American nurse comforting a dying cancer patient has gone viral.

The video was taken at Vanderbilt University Medical Center in Nashville where Margaret Smith was awaiting a liver transplant.

It shows her nurse Olivia Neaufelder comforting Margaret by singing her favourite song, ‘Dancing in the Sky’ by Dani and Lizzy.

See the video below

The 63-year-old patient had been battling liver cancer for over a year and just learned she was too weak to survive a transplant.

Olivia decided to sing to cheer her up.

“Okay, it’s our favourite part,” she tells Margaret at one point, encouraging her to sing along.

Crystal Roberts, a long-time friend of Margaret, recorded the video from her bedside.

Sadly, despite the best efforts of staff, Margaret passed away three days later.