A coalition of 14 New Zealand-based aid agencies, including global heavyweights Oxfam and World Vision, have petitioned Ms Ardern and Foreign Minister Winston Peters to join an urgent humanitarian effort.

Ian McInnes, Council for International Development chair and chief executive of signatories Tearfund, says New Zealand is enjoying a moment of global strength and should use it.

"Right now, we think New Zealand has a outsized voice," he told AAP.

"We've been incredibly diligent and our team of five million has cracked our cases here in New Zealand.

"We don't like to boast in New Zealand. But if we lead out on this and we say we believe others should follow, we feel that carries weight at this time."

The humanitarian appeal has been launched after a United Nations University study projected recessions in developing countries would sink hundreds of millions below the poverty line.

A low end scenario of a five per cent contraction would see 130 million more in poverty.

A worse-case contraction could see 420 to 580 million more impoverished.

"That's six to eight per cent of the global population and we think that sets global development back a decade," Mr McInnes said.

"Petty traders on the side of roads in India are being harassed and sent home because it's lockdown. These are the people that sell food to the poor.

"Anyone who lives hand to mouth, day labourers, if they can't work, they can't eat."

The United Nations has asked richer nations to contribute $US2 billion ($A3 billion) to an immediate humanitarian relief fund, with New Zealand asked to give $NZ25 million ($A23.4 million).

Mr Peters said he was yet to consider the aid request, but New Zealand had earmarked $NZ50 million ($A46.8 million) towards COVID-19 readiness and response in the Pacific.

"Including $10 million right now to get the utilities, masks, things they need, including looking at medical utilities and people to go to (Pacific) countries," Mr Peters said.

"We have done an enormous amount to be a responsible citizen."

Mr McInnes said that wasn't enough.

"He's directing existing aid. We would say you shouldn't," he said.

There are fears New Zealand's foreign aid budget could be raided as it looks to balance the books after spending more than $NZ22 billion ($A20.6 billion) in recession-fighting stimulus.

New Zealand contributes 0.28 per cent of its gross national income towards foreign aid, with a goal to reach 0.7 per cent.

Asked last week, Ms Ardern wouldn't be drawn on aid funding in next month's budget.

"What I would say is that New Zealand has always been mindful of our responsibility to particularly our Pacific Island neighbours, in times of hardship and in good times, and it's no different for us now," she said.

Australian Associated Press