The cleanup in Tonga is underway as authorities work to clear debris amid fears mosquito breeding grounds will develop, a New Zealand journalist in Tonga says.
Cyclone Gita was briefly upgraded this afternoon to a category five storm but has now been downgraded to category four and is moving slowly south-west.
The storm made landfall in Tonga on Monday night as a category four cyclone, ripping roofs off houses, destroying crops, and destroying a church as well as Parliament House.
The Royal New Zealand Air Force is helping Tongan authorities with the assessment.
A 10-person team is on the island and 12 tonnes of supplies were flown in including hygiene kits, temporary shelters and water containers.
An Orion has also conducted aerial surveys.
NEWS || Our C-130H Hercules arrived in Tonga last night delivering 12 tonnes of aid and an initial assessment team to communities affected by #CycloneGita.— NZ Defence Force (@NZDefenceForce) February 13, 2018
MORE: https://t.co/noZQ4WcdUg. #Force4Good pic.twitter.com/UO1vsIpfkH
TVNZ's Pacific correspondent Barbara Dreaver has been in the Tongan capital of Nuku'alofa since the cyclone struck.
Authorities were still assessing the damage and working to reconnect power and water supplies, she said.
Anything people had managed to salvage was now out drying in the sun, she said. Ripped clothes could be seen hanging on fences.
The roads were mostly clear and trucks were moving debris.
"It's important that debris does get clear and it doesn't become a mosquito breeding ground," she told Checkpoint with John Campbell.
She said there had been a recent dengue fever outbreak and one person had died.
"These breeding grounds can develop really quickly and if you have got stagnant water ... like a lot of the homes that we have been to, that is an issue - a big issue."
A lack of fresh water could also create public health problems and authorities were very aware of that potential, she said.
Some schools were very badly damaged and only a few shops were open.
The Red Cross was visiting hundreds of families, she said, and providing tarpaulins, tents, cooking utensils and tools.
"I saw one family's face when they got their supplies and it was magic. You know, these are the sort of tools that they've been waiting for," she said.
New Zealand's acting High Commissioner, Elena Procuta, said Tonga's disaster authorities were trying to work out how many households were facing water shortages and related hygiene issues.
Ms Procuta said the number of people displaced was still not known and assessments were continuing.
Pacific weather forecasters say that Cyclone Gita, which strengthened to a category five system earlier today, is likely to weaken slightly over the next 24 hours.
Gita is moving away from Fiji's southern islands in a west-south-west direction but is expected to tend southwesterly later.
On this path it will pose little threat to Vanuatu but will approach close to New Caledonia.