Asia-Pacific countries must work together to crack down on the financing of terrorism and criminal groups, Justice Minister Amy Adams says.
About 360 officials from 41 countries are in Auckland for the annual meeting of the Asia-Pacific Group on Money Laundering.
The group says there are increasing threats from international organised crime groups and terrorism, and its meeting will focus on how to stop such groups being financed.
Ms Adams told the conference the rise of Islamic State showed methods of financing terrorism were changing rapidly.
Particularly troubling was the use of grass roots strategies such as fundraising through social media which were both "highly effective and difficult to trace," she said.
Ms Adams referred to estimates in the media that Islamic State had a turnover of more than $2 billion.
She said it was critically important to detect fundraising, and disrupt cash flows in and out of territories held by the terrorist organisation.