However, its final use and future ownership will be decided by a steering group made up of three representatives of the Ahi Kaa (occupiers of the land), two Kīngitanga and two from the Crown.
The agreement leaves open the possibility of a future transfer of ownership to the tangata whenua, if that is what the group settles on.
Robertson said that would be up for discussion, but if the land had been bought for housing it had to be used for housing purposes.
"If there were to be significantly different outcomes on the land beyond housing there would be other conversations to be had about funding."
He said it was far too early to say whether the land would have to be purchased from the Crown, if that was the case.
Soul co-founder Pania Newton said it was an important first step, and acknowledged the efforts of whānau and others who had maintained the occupation and pressure on the issue.
"We are relieved the Government has finally come out and made their announcement because that is the first step to healing the heartache that lies across this whenua."
However, Newton said it was disappointing that the Government did not acknowledge it as a Treaty-related settlement, given the land was confiscated from Māori in the 1800s.
Ihumātao had never been considered in a Treaty settlement because it had been private land since then and private land can not be used in settlements.
The agreement specifically excludes the use of the land in any future Treaty settlement, or to try to re-open settlements that had already been concluded.
Robertson rejected claims by National and Act that the deal set a precedent that would result in occupations of other private land in a bid to get a similar deal, or that it undermined the Treaty settlement process.
"This is a unique solution for this particular area. It is a unique settlement outside of the Treaty settlement process. We are not doing anything to unpick the Treaty settlement process."
However, Māori Party co-leader Rawiri Waititi said the deal should be taken as an "an important precedent" for the Crown addressing injustice by returning confiscated land to Māori outside of the Treaty settlement process.
"We know that there are many other 'Ihumātao' right around the country – sites of huge significance that mana whenua are fighting to have returned.
"It is the Māori Party position that no Treaty settlement is full and final if it is unjust, and that Treaty justice must mean the return of whenua Māori into the hands of whānau, hapū and iwi."
Green co-leader Marama Davidson also referred to it as a settlement that righted an historic wrong – terminology often used with Treaty settlements.
Robertson said Prime Minister Jacinda Ardern would take advice from Kīngitanga on when and whether it was appropriate for her to visit the site.
The agreement estimates it could be up to five years before the steering group concludes its talks on the future use of the land.
Newton said it would be up to whānau to decide what to do with the land, but she did not necessarily believe it should be used for more housing.
"Most conversations have been around preserving and protecting this cultural landscape."
Robertson said all parties had agreed it would be used for some housing, and that could take many forms including housing for elders, papakainga and some state housing.
It could also be used for a mix of heritage, culture or conservation purposes.
