Insurance and Financial Services Ombudsman Karen Stevens said she was expecting many calls and enquiries to her office from concerned travellers.
The Insurance and Financial Services Ombudsman Scheme resolves complaints about insurance and financial services.
People are advised to get in touch with their policy providers.
"For those currently in New Caledonia, check with your insurer and airline about the options available to you as soon as you can. For those who have an upcoming trip to New Caledonia, talk to your insurer about what they will cover now, before you leave," she said.
"If you have booked a trip to New Caledonia, but haven't bought travel insurance yet, it's unlikely that the insurance you buy now will cover you for any cancellations that arise from the unrest in future."
Stevens said all travellers should purchase travel insurance when they booked tickets.
Up-to-date travel warnings for New Caledonia can be found at Safe Travel.
The website asked all New Zealanders in New Caledonia "to avoid all protests and demonstrations, as even those intended to be peaceful have the potential to turn violent".
"The Tontouta International Airport has been temporarily closed, and we understand that the airport may remain closed until midnight Thursday 16 May.
"We recommend that all travellers check with their airline before proceeding to the airport. The road between Noumea and Tontouta has been impacted by road blocks. We recommend that you also contact your travel insurance provider to see what insurance cover may apply in these circumstances."
Rioting has continued overnight in New Caledonia's capital Noumea, with reports of gunfire and arrests as people defied the curfew.
The rioting was provoked by a proposal by France, which would allow French residents who have lived in New Caledonia for 10 years, to vote in provincial elections.
