NZ First leader Winston Peters has accused the Greens of selling out New Zealanders with their policy to increase the refugee quota.

They want the annual quota increased to 4000 over six years, on top of that 1000 coming in through church and community sponsorship.

The party would also create a new visa category for people displaced by climate change in the Pacific, starting with 100 places a year.

At present the quota is 750, rising to 1000 next year.

"New Zealanders have been sold out by the Greens big time," Peters said.

"Kiwis are living in cars, garages and slum-like boarding houses but that's no matter to the Greens.

"The Greens know nothing of the soaring population, caused by mass immigration... wages are stagnant, there's real poverty and degradation right outside the door - and they want to add thousands to the waiting list for houses."

The Greens have an existing policy of immediately doubling that, and Tuesday's announcement is a significant extension of that policy.

"The Green Party will immediately double New Zealand's refugee quota to 2000, then we will progressively increase the quota to 4000 over the next six years," it said.

"Over that time we will establish new resettlement locations across New Zealand and work with communities to build up the capacity of organisations that support new refugees and asylum seekers."

The Greens estimate their policy would cost $66 million in 2018, rising to $350 million when the quota reaches 4000.

Church and community sponsorship would expand to 1000 over the next three years.

The policy document said in Canada, tens of thousands of refugees are helped to resettle this way each year.

The government said last year it would run a trial sponsorship programme involving around 25 places.

It's still discussing the scheme with churches and other potential sponsors.

The Greens said New Zealand currently accepts far fewer refugees per capita than many other countries.