Health authorities in New Caledonia say they have introduced border control measures to identify travellers who may have the mosquito borne illness, zika virus.
They say a man and a woman returning from French Polynesia have been confirmed with the illness but neither has needed hospital treatment.
The head of the Health Services, Dr Jean Paul Grangeon, says people need to be honest when they fill out their health declaration forms on arrival in New Caledonia.
He says not much is known about the zika virus yet but it's similar to dengue fever.
"It's quite the same symptoms except in zika virus there is more cutaneous rash. But we in New Caledonia can make a blood test to make the difference. So each people coming with a fever or pain in joints or muscles or headache or cutaneous rash; especially if they're coming from overseas; they are being tested for the three viruses: dengue, chikungunya and zika virus."
Dr Jean Paul Grangeon says public health vector control measures are in place and people are being advised to use insect repellant.