De Beers will operate the Gahcho Kué project in which it holds 51% stake, while Mountain Province Diamonds holds the remaining share.
The IBA allows De Beers and the Lutsel K’e Dene First Nation to work together over the life of the mine.
First Nation chief Felix Lockhart said: "This agreement ensures that we have our families out on the land, using our land.
"We are shaping resource development the way we want it, according to First Nations. We are going to be monitoring it."
De Beers Canada COO Glen Koropchuk said: "Our relationship with Lutsel K’e is important to us and this Impact Benefit Agreement confirms our commitment to work together for the benefit of Lutsel K’e Dene First Nation members as we advance the Gahcho Kué Project and build a mine."
During the construction phase, Gahcho Kué will create around 700 jobs and approximately 400 jobs on commencing operations.
