UPDATED 4.58pm New Zealand is committing extra aid funding to what could become the world's largest crisis since World War II.

Foreign minister Murray McCully has confirmed an extra $3 million will be spend on famine relief and prevention programmes in Africa and Yemen.

However, $1 million of those funds will only be provided to NGOs if they can match the funds through public donations.

The Council for International Development's Humanitarian Coordinator Darren Brunk thinks they can get there.

"CID agencies raised $16.5 million for development and humanitarian activities in the region last year so in terms of being able to meet that million dollars, we're confident we can do it."

The money will go towards food, water and healthcare programmes in South Sudan, Yemen, Nigeria and the Greater Horn of Africa.

World Vision international partnerships manager Alex Snary said droughts, conflict and insecurity have compounded to create one of the world's worst ever humanitarian crises.

"The sooner we can increase the amount of assistance and get food for people who desperately need it, the fewer causalities we will see in the end," he said.

Snary said a range of simultaneous events are causing mass migration, and could lead to widespread fatalities.

"What we're looking at is the perfect storm. Some of the affected countries have been suffering from extended drought, others affected by conflict such as South Sudan."

LISTEN: New Zealand Red Cross' Hanna Butler spoke to Jack Tame about the famine relief