Kellie was speaking after Alliance Lord Mayor of Belfast Councillor Nuala McAllister unveiled the new vehicles at the Busworld Europe exhibition in Belgium.
She added: “This project will not only make it easier for users to travel across Belfast, but is a crucial step towards ending congestion on our roads and will have a significant impact on our tourist economy – making the city much easier to navigate for everyone.
“Belfast is a busy commuter city, with cars, cyclists and motorists often crammed and fighting for space. Not only will this increase in years to come, but can only have an adverse effect on our local environment and so it is essential we get the mix right, making room for everyone.
“We must take all steps possible to protect the world around us. These new vehicles will help us deliver a cleaner, greener environment for all who live and work here and I can’t wait to see them start arriving in Belfast later this year.”