The Green Party and the National-led Government have formally agreed to work together on issues including home insulation, Prime Minister John Key says.
Mr Key says both parties are also eager to look at reviving some sort of trans-Tasman therapeutics agency.
He says the memorandum of agreement marks a "baby" step in terms of the relationship between National and the Greens, and will not involve the Greens providing support on confidence and supply.
However, Mr Key says there are areas of common interest, and the Government is open to some of the ideas being put forward by the Green Party.
The Greens will gain access to certain government ministers and departmental officials, and will have input into ministerial decision making.
The party says it enters the agreement with cautious optimism, but is hopeful of making some positive changes.
Co-leader Russel Norman says his party did not reject the idea of working with a National-led government before the last election.
He says New Zealanders who can't afford to insulate their houses will benefit from the arrangement.