Massacre condolence books opened
Members of the public will be able to leave messages of support in the books from Monday morning.
Twenty-seven people including 20 children were killed after a gunman went on the rampage at Newtown's Sandy Hook Elementary School on Friday.
He said: "The murder of so many young children in the month of Christmas just emphasises the pain and hurt that the families of all the victims must be going through.
"This is a crime that has shocked the world and it is only right that the citizens of Belfast and Northern Ireland have an opportunity to leave messages of sympathy and support for the families.
"We can only begin to imagine the pain of loss that the families must be going through."
Suspected gunman 20-year-old Adam Lanza killed his mother at their home before going to the school and opening fire on children aged between five and 10.