Ngāti Whātua Ōrākei will hold a karakia and blessing on Thursday morning, at the site of the fatal shooting in Auckland's CBD.
At 6.45am there will be a short ceremony in Te Komititanga square, which will be open to the public.
Once the karakia concludes at 7am the public across the country will be asked to observe a moments silence to remember the men who lost their lives.
The karakia will mark one week since the gunman Matu Reid entered the central Auckland building, killing two people and injuring several others before taking his own life.
Ngāti Whātua Ōrākei deputy chair Ngarimu Blair said the karakia would clear and reset the space for normal use, while also providing an opportunity for those close to the tragedy to grieve their loss, and for those who live and work in the CBD a chance to reflect on what has happened.
Blair said it was the continuation of a role that the iwi had held for centuries.
"It's just a part of that ongoing work, an obligation and honour that we have to do this kind of mahi, to help those who feel they need it to continue to live, work and play in the CBD."
The iwi had a part in the openings of most of the buildings in the CBD and the karakia would be an extension of that, Blair said.
Ngāti Whātua were humbled to be able to provide spiritual and cultural support to those who had been affected by the shooting, he said.
"We extend our hearts and our whakaaro to those who lost loved ones and those who have been traumatised by the event. We certainly felt it as the tangata whenua of this CBD and we all live and work in there as well.
"We're feeling really sad for all the people involved and we hope in some small way that this may help."
Once the construction site had been cleared by police a small group would be able to enter the building and perform karakia on the inside, Blair said.