The death toll in Fiji from Cyclone Winston stands at 42 with Prime Minister Frank Bainimarama warning his
devastated nation it faces a long and difficult recovery.
"Almost no part of our nation has been left unscarred," Mr Bainimarama said in a national address on Wednesday.
He said Winston, believed to be the most powerful storm ever to hit Fiji, had left "a terrible trail of destruction in its wake" and created a need that is great and urgent.
"Right now the priority is on restoring essential services and supplying our people with sufficient food, water and shelter," he said.
Aid agencies, including the United Nations, are working to provide desperately needed aid to Fijians after Cyclone Winston devastated the area.
A statement from the United Nations said there were almost 14,000 people sheltering in 274 evacuation centres around Fiji after the storm hit on Saturday and Sunday.
"At least 364 dwellings have been destroyed, and 65 schools have been damaged or destroyed," the statement said.
"Schools have been closed for the week and the government has indicated that restoring education is its top priority for the response over the coming days."
The UN and other agencies are coordinating with the UN Office for the Coordination of Humanitarian Affairs (OCHA) to provide relief to islands like Koro where whole villages have been wiped out.
Equipment including water containers, tarpaulins, generators, chainsaws and tool kits have already been distributed from Nausori airport in the capital city of Suva.
Australia has committed to a $5 million assistance package which will include military helicopters to assist with aerial surveillance and air transport of relief supplies for 1500 families.
The UN Children's Fund is also assisting with the provision of child friendly spaces in evacuation centres while the World Health Organisation has received a request for 36 000 water purifying tablets.
Death toll fears
There are fears the death toll could rise in the nation of 900,000 people when communication resumes with the smaller islands hit by Cyclone Winston on Saturday.
Aerial footage of outlying islands taken by the Royal New Zealand Air Force, and posted on the Fiji government's official website, showed whole villages flattened and flooded after Winston's destructive winds, up to 325 kph (200 mph), tore through the archipelago of 300 islands. Thousands of Fijians live in tin or wooden shacks in low-lying coastal areas.
Authorities have warned of "catastrophic" damage to Koro Island, Fiji's seventh-largest island, and more than 8,000 people continue to shelter in evacuation centres across the country.
Prime Minister Frank Bainimarama reassured Fijians that the government was doing all it could amid growing criticism of the slow emergency response in some parts of the country.
"We realise the desperate position that you are in," Bainimarama said in a statement after visiting an evacuation centre. "We will not rest until we have reached you and given you the helping hand you so badly need and deserve."
"Unfortunately the recovery process will take time, perhaps a long time," he added. "Almost no part of our nation has been left unscarred."
Aid workers warned of potential outbreaks of the Zika and Dengue viruses, both carried by mosquitoes which will breed in the stagnant water left by the storm.
"The threat of dengue and Zika in the coming days in Fiji is real," said Chris Hagarty, senior health programme manager at Plan International Australia.
"The period immediately following a disaster of this scale can be a particularly dangerous one."
The World Health Organization declared a Zika outbreak in South America an international health emergency on Feb. 1, citing a "strongly suspected" relationship between Zika infection in pregnancy and microcephaly, a condition marked by unusually small heads that can result in developmental problems.
Much remains unknown about Zika, including whether the virus actually causes microcephaly. Brazil has confirmed more than 500 cases of microcephaly, and considers most of them related to Zika infections in mothers. Brazil is investigating more than 3,900 additional suspected cases of microcephaly.
Fiji's international airport at Nadi has reopened and an aeromedical evacuation team was being sent to outer islands on Tuesday to provide urgent support and supplies, including water and hygiene kits, medicines and access to shelter.
Watch aerial footage from Fiji: