The Labour Party leader says the cooperation agreement reached with the Greens means the two parties can agree to disagree.
Jacinda Ardern and deputy Kelvin Davis, along with Green Party co-leaders James Shaw and Marama Davidson, have signed a cooperation agreement that gives the Greens ministerial portfolios outside of Cabinet.
Watch a video of the signing here
Shaw will remain as the Minister of Climate Change and will also become an associate minister for the environment. Davidson will hold the new prevention of family and sexual violence portfolio and associate housing.
After the agreement was signed at the Beehive this morning, Shaw called it a "win-win" for both parties.
Ardern said it was a unique arrangement, considering Labour actually had the numbers to work alone.
"We've embedded in this arrangement that we do not have to agree on issues, that means that actually if we need to get on with things, we can. The Green Party can make it clear where they don't agreee, while we get on with things, but it doesn't stop our ability to work together."
About 85 percent of roughly 150 Green delegates voted in favour of the deal on a lengthy conference call last night.
The delegates were presented the deal following several rounds of talks between Labour and Green leaders that concluded on Thursday.
The agreement includes little policy detail, but a commitment to work together on child poverty, climate change, and the environment.
It also means the Greens can't oppose Labour on confidence and supply matters, but can take their own position on issues outside of ministerial portfolios and areas of co-operation.
Ardern will announce her new Cabinet line-up at Parliament tomorrow.