Vancouver has been ranked as the world's third most-livable city again in an annual survey by an independent business associated with The Economist magazine.

As in 2012, Toronto and Calgary placed fourth and fifth, and Melbourne took the top spot for the third year in a row.

Vienna came in second in the ranking of 140 cities based on 30 factors including the quality of health care or the threat of military conflict.

Vancouver spent almost a decade in first place before Melbourne moved to the top of the list in 2011.

The lowest livability score was shared by Damascus, because of Syria's ongoing civil war, and Karachi, Pakistan.

London and New York have been ranked as numbers 55 and 56 respectively, mainly because of a perceived risk of terrorism, according to the report.