Books of condolence for the victims of the Newtown school shooting will be opened at Belfast City Hall.
Members of the public will be able to leave messages of support in the books from Monday morning.
Ulster Unionist Jim Rodgers said the people of Belfast wanted to show solidarity with those affected by the tragedy.
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.
A list of the victims from the US school shooting has been published. Twenty students and six teachers were killed in the massacre.
The most disturbing feature of the rampage is what we do not know. We still have no idea why Adam Lanza acted with this cowardly savagery.
There are reports claiming that Adam Lanza went to the school a day before the massacre. They say he had a major confrontation with staff.