The death toll from a ferocious cyclone that tore through Fiji over the weekend rose to 29 as authorities on Monday began to get a grasp on the scale of the disaster and deploy aid to hard-hit outer islands.

Authorities were still having trouble communicating with some islands, including places like Koro Island which suffered some of the worst damage.

Winds from Cyclone Winston, which hit Fiji over the weekend, reached 285 km/h, making it the strongest storm in the Southern Hemisphere since record keeping began, according to the Weather Underground website.

Koro Island

Authorities were still having trouble communicating with some islands, including places like Koro Island, which suffered some of the worst damage. (Google/CBC)

Getting emergency supplies to the group's far-flung islands and remote communities was the government's top priority said Ewan Perrin, Fiji's permanent secretary for communications. Home to 900,000 people, Fiji has more than 100 inhabited islands.

"The logistics of getting supplies and equipment to remote communities is difficult," he said.

Perrin added that the death toll on Koro Island had reached double figures and that most buildings there had been heavily damaged or flattened.

The United Nations stands ready to support Fiji with any expertise and support it may need, Stephen O'Brien, the UN's under-secretary-general for humanitarian affairs and emergency relief co-ordinator, said in statement Monday. 

"Whole villages have been destroyed, homes and crops have been damaged, power lines have been cut and more than 8,100 people are currently sheltering in over 70 evacuation centres," O'Brien said.

O'Brien said the government of Fiji is leading the response, providing food and other supplies as well as emergency shelter.

The government has declared a natural disaster and asked for international assistance, he said.

Perrin said France, the U.S. and China have also provided or pledged support. He said relief agencies, including Oxfam and the Red Cross, have been helping with humanitarian efforts and that the Fijian government has set up a disaster relief fund.