The Green Party co-leaders say talks with Labour are in the closing stages and they expect to take a deal to their membership by Friday.
Having won an outright majority on election night, Labour does not need a helping hand to form a government, but Green Party co-leaders James Shaw and Marama Davidson have formally met with Labour leader Jacinda Ardern three times to discuss potential areas of cooperation.
Shaw today said the parties had made "pretty good" progress and expected to conclude talks by the end of the week.
A final deal has not been reached, but RNZ understands Shaw has been offered the climate change portfolio, as a minister outside of Cabinet.
He refused to confirm this, saying "we can't speculate on speculation ... we won't be commenting on the content of the negotiations until we've concluded".
RNZ also understands Marama Davidson will likely be offered a ministerial portfolio, but which one is yet to be decided.
She also would not comment on these reports, but said she was happy with the progress of discussions.
Shaw said forming a government was a "complicated business".
"It took us four weeks in 2017, but of course the complicating factor there is that there were three parties, so we're confident we'll be able to do it a lot faster this time."
Davidson said talks were getting towards the end, which "indicated good progress".
"It's just about narrowing things down, getting things down to the final point and we're making good progress," she said.
Discussions may continue over the next few days, she added.
Once a final offer has been put forward, the co-leaders will present it to its members on a call. They will then vote on the deal, and a 75 percent majority is needed to accept it.
A spokesperson for Ardern said conversations continued to progress well today with talks on track to wrap up "by the end of the week".
Read more about the election results:
- Live updates: Election 2020 concludes; what next for New Zealand's political parties?
- The red tide: Labour wins 15 seats held by National
- National's Gerry Brownlee admits he made a 'huge mistake' during electioneering
- Labour wants to build as much consensus as possible - Megan Woods
- Comment: Jacinda Ardern has huge majority but that may not be much use to her
- Election 2020: The show is over for Winston Peters