The Fiji met service says tropical cyclone Bune is forecast to intensify to a category three storm in the next six to 12 hours.
The cyclone is south of Fiji and moving very slowly in a south-easterly direction.
The lead forecaster at the met service says once it develops into a category three, he expects it to maintain that intensity for up to 48 hours.
David Grant says at this stage, cyclone Bune poses no immediate threat to land.
"So the only issue will be for mariners throughout there really and I imagine once it does move down towards New Zealand it may bring some rain associated with it but I expect it to remain out in open waters in the next few days."
David Grant of the Fiji Met service.