Pacific forecasters have named a Category 1 cyclone which formed this evening northeast of Vanuatu, Donna.
The system is rapidly intensifying and could become a Category 3 by midday tomorrow.
Fiji Meteorological Service senior forecaster Stephen Meke said the system was forecast to move over Vanuatu within the next two days.
"We expect it to rapidly intensify within the next 24 hours, possibly attaining Category 3 by tomorrow midday. It is expected to move over Vanuatu within the next 48 hours.
"It is not really a big system - it is a quite small system, but it is very intense, that is what we are worried about. If it impacts on any islands, it will be very destructive.".
On Wednesday evening at 7pm New Zealand time, Donna was a Category 1 cyclone and its centre had the coordinates 13.1 degrees south and 171.2 degrees east.