Tonga was braced Sunday for "very destructive winds" as Cyclone Gita took aim at the Pacific island nation a day after it wreaked havoc in Samoa.
The kingdom's tropical cyclone centre has been activated and Red Cross, which is coordinating relief supplies, has warned islanders to be prepared.
"Very destructive hurricane force winds are expected from Monday morning," Tonga's Fua'amotu Weather Forecasting Centre said in a bulletin, forecasting gusts of 80 knots (148 kmh, 92 mph) with heavy rain and thunderstorms.
Tonga Red Cross secretary general Sione Taumoefolau said there was particular concern for the outer islands where houses may not be able to withstand the brutal force of the winds.
Samoan Prime Minister Tuilaepa Sailele Malielegaoi said Gita forced the evacuation of some 200 people and caused widespread flooding when it slammed into the island overnight Friday.
Gita had since intensified from a category two to category three storm as it took aim at Tonga and was expected to get stronger.
"The possibility is very high to intensify along the way up to our area, so we expect up to category four but we still monitoring the movement and strength," Tonga's acting chief meteorologist Gary Vite told Radio New Zealand.