The heart-shaped 'B' logo is expected to help promote Belfast as an exciting, vibrant and welcoming place.

The colourful logo, which will be placed across the city on billboards, buses and council literature is accompanied by messages including the word 'be' — such as 'be welcome', 'be part of it' and 'be vibrant'.

Lord Mayor of Belfast Tom Hartley said the new brand was about the future, although the message behind the design was questioned by the public and fellow brand professionals.

The company behind the controversial 2012 London Olympics branding said the new design for Belfast wasn't unique.

Robert Jones from Wolff Olins, a brand consultancy based in London and New York said: "Belfast is an amazing success story — one of the most dynamic cities in Europe.

"A proper brand can help amplify this success. But it's not clear what this brand is about — what is the Belfast brand meant to stand for? And using a heart symbol, as New York did years ago, lacks confidence — Belfast is unique, and its brand should look unique."

However, Ulster Unionist councillor and former Lord Mayor Jim Rodgers, who played a role in its development, said he is excited about the new brand.

"Obviously you will have those who are unhappy with the design, but if you look closely at it and the way it has been done it is very tasteful. It is basically saying Belfast has a heart," he said.

"It took longer than we would have liked but we wanted to get it right. We tried to get all the interested parties involved from the private and public sector, sport community and voluntary areas. We needed to rebrand, the smile had been with us for a long time. There has been wide consultation and I hope that the wider public will like it too."