National Party leader Bill English says it could take several weeks to work out a deal with NZ First that would allow him to form a government.
Mr English's party won a commanding lead over Labour on Saturday, but he still needs to negotiate a deal with Winston Peters and give NZ First a better coalition offer than Labour and the Greens.
Mr English told Morning Report National would start planning its negotiation strategy with a meeting of senior party members today, but added that two to three weeks would be a "reasonable" period of time to spend on negotiations.
"We have to spend time on this, out of the light of the media."
He said Mr Peters' role in Parliament had been to be a "bit of a maverick", but that he was a known quantity in many respects.
"He understands his role, he's very experienced. Some of his long-held positions I think he would expect to be reflected in government policy."
Listen to the full interview with National Party leader Bill English
"I have known him a long time, he's a politician who has specialised in a sense in MMP and understands his role. He has some well-understood and long-held positions, and we would expect that given that understanding of how he works, we can deal with him."
Mr English said he was not ruling anything out when it came to negotiations, but admitted that making Mr Peters Prime Minister was off the table.
While special votes still needed to be counted, Mr English said it was hard to see anything from the special votes that would be "decisive" enough to affect the start of negotiations.