Firefighters were able to save the accommodation blocks, he said.
It is understood the resort was at 85 per cent capacity including many New Zealanders and Australians.
The guests were moved on to Naviti's sister resort, the Warwick Resort, a few minutes up the road.
The resort on the Coral Coast of Fiji's largest island, Viti Levu, is popular with New Zealand families.
Naviti Resort said on its website that it was "a sad day'' but it was most important that everybody was safe.
"Firemen have successfully contained the fire and nobody has been injured in this tragic incident.''
The resort remains closed and an investigation is underway.