The Fiji Met services says a tropical disturbance, which has been hovering over the northern Cook Islands over the last few days, has developed into a tropical cyclone.
It says cyclone Victor, a category two system, is moving southwest at nine kilometres an hour, and that close to the centre the cyclone is expected to have average winds of 92 kilometers an hour.
Forecasters say Rakahanga, Manihiki, Suwarrow, Nassau and Pukapuka can expect damaging gale force winds with average speeds of 64 kilometres an hour to 92 kilometres an hour, periods of heavy rain and few squally thunderstorms.
Sea flooding of low lying areas likely, and high seas are expected
The rest of the northern Cook Islands can expect strong winds with average speeds of 46 kilometres an hour and gusting to 74 kilometres, periods of heavy rain and few squally thunderstorms.
Sea flooding of low lying areas likely, and high seas are expected.