UN Secretary General Ban Ki-moon joked that he feels like Cinderella, as he prepares to step down at midnight on 31 December 2016.

"At midnight, everything changes," he told a room full of UN staff.

"On the eve of the new year, I'll be in Times Square [New York] for the ball drop. Millions of people will be watching as I lose my job!"

He said he had two words for the UN staff in the audience: "Thank you!"