New Zealand will also make $50,000 immediately available to Fiji and $170,000 to the Fiji Red Cross which will help to replenish supplies for those in immediate need, he said.
"Tarpaulins, water containers, generators and chainsaw packs are also on the way to Fiji on commercial flights.
"Our thoughts are with the people of Fiji as they respond to Tropical Cyclone Evan," said Mr McCully.
Tropical Cyclone Evan has passed Fiji, but strong winds and large swells and expected to continue today.
Fiji was pounded yesterday by 270km/h winds, which uprooted trees and homes, ripped roofs off buildings and caused widespread power and water outages.
The Fiji Ministry of Information reported a total of 8016 people were sheltering at 137 evacuation centres, with 3646 in the north, 356 in the east, 2021 in the central division, and 1993 in Rakiraki.
There were no reports of fatalities this morning.
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Evan is forecast to lie about 290km south of Nadi by 4pm today and flood warnings are in place for Mainimala, Wainibuka, Waidina, Rewa and Navua rivers, and low lying areas of Nausori.
With more rain to come, the Wainibuka River is 7.2 metres above critical.
The Rewa River is only 30cms below critical levels and still rising, while other rivers had also exceeded critical levels.
TWO SHIPS RUN AGROUND
With winds stirring up massive swells, two ships ran aground near the entrance to Suva Harbour.
The bulk carrier Starford, believed to be carrying equipment for a Chinese railway company, dragged its anchor at 11.30am and was pushed on to the reef close to the entrance.
The container vessel Captain Tasman was last night aground on the east side of the harbour entrance with a full load of containers.
Yesterday, there were reports of more than 12 houses being blown away in Lautoka and families reported losing all their belongings after winds tore apart the homes.
A resident in the area said of the 18 homes there, only five houses remained standing, Fiji Village reported.
In Nadi hundreds of New Zealanders were sheltering in boarded-up hotels.
Steve Delany, holidaying at Denarau Island, told 3 News that despite the wild weather, he felt as safe as was possible in the situation.
"I think the major concern is for Fijians themselves, who don't have half the protection that we have."
Pacific Harbour resident Michael Thoms, who lives 40 minutes from Suva on the south coast, told APNZ the worst weather had passed the area by this morning.
"The wind has just dropped away almost to nothing. At about 2 o'clock this morning I woke up because there was no wind."
Mr Thoms said it was a warm day with a light northerly breeze - but he feared worse news in the north and west over the next two days.
The cyclone had been the worst he had experienced in his 45 years - worse even than Cyclone Bebe, which hit the region in 1972 and killed 18 people.
Cyclone Evan: How you can help
"This will be the benchmark I think from now on that we judge our cyclones by."
Mr Thoms said Pacific Harbour still had power but there was no water.
Most of the damage in the area was to foliage, with trees down and a lot of debris.
Joanna Underwood of Nadi said she had eight family members at her home and friends who had flood-prone homes were arriving.
"We have nothing else to do here at the moment except stay inside and watch the wind blow everything outside."
WEATHER FORECAST
The Fiji Meteorological Service said the cyclone had weakened to a category 3 and was centred about 210km south of Nadi at 7am, and is moving south-southwest at 15kmh.
It is forecast to lie about 290km south of Nadi by 4pm today.
With more rain to come, the Wainibuka River is 7.2 metres above critical.
The Rewa River is only 30cms below critical levels and still rising, while other rivers have also exceeded critical levels.
The next high tide is around 11.30am.
A hurricane warning for the Coral Coast, Vatulele, and nearby islands has been cancelled, as has a storm warning previously in place for the Mamanuca group.
However a gale warning remains in place for the Coral Coast, Kadavu, Beqa, Vatulele and nearby islands, with momentary gusts up to 110kmh possible, and strong wind and damaging heavy swell warnings remain in force for Fiji.
Sangay Prakash of the Fijian Metservice said heavy winds between 60 and 110 knots per hour had hit the Nadi and Lautoka areas with "destructive force".
He said the most damaging winds would likely come overnight.
Yesterday, there were reports of more than 12 houses being blown away in Lautoka.
Families reportedly lost all their belongings after winds tore apart the homes.
A resident in the area said that of the 18 homes there, only five houses remained standing, Fiji Village reported.
Flights in and out of Fiji have resumed this morning, with the first flight for Auckland due to depart at 8.45am. Airlines have put on more services to clear the backlog after flights were cancelled yesterday.
For flight details check Airports Fiji here.
The cyclone, the first of the season in the South Pacific, was expected to move away from Fiji later today, but not before pounding Nadi further.
NEW ZEALAND'S RESPONSE
Prime Minister John Key this morning said the Government had received a formal request for help from Fiji overnight.
"We're in the process of working through that this morning. The same is true with Samoa - we're working through an assessment of the damage and where we might best be able to help," he told TV3's Firstline.
Mr Key said part of the help would be monetary assistance.
"There's reasonably widespread damage in both Samoa and Fiji, so they'll need to restore a lot of their core infrastructure and there will be damage to that critical infrastructure."
Mr Key said the Government had not yet settled on a figure for how much assistance would be offered, but an announcement on an immediate up-front sum was likely in the next two days.
"And then typically the pattern is we tend to top that up after we've had a bit of chance to look further afield."
Mr Key would not name a figure, but in the past it had been in the millions rather than tens of millions.
"That's typically been the pattern, but let's have a look and see what they need and where we might be able to deploy some of our services to help them."
Foreign Minister Murray McCully said Lautoka, Fiji's second biggest city, had suffered significant damage, and Evan was going to pass closer to Nadi that had been hoped.
Despite the political differences between Fiji and New Zealand, providing aid to Fiji is not a particular challenge, Mr McCully told Newstalk ZB.
"Last time they had flooding problems we provided a Hercules that worked very closely with their military - conducted a sort of air-bridge service.
"I suspect something similar will be called for this time around as well."
Mr McCully said New Zealand had an acting high commissioner who had been very active in the last few days and was ready to help.
So far there had been no reports of New Zealanders being in difficulty.
"In Nadi, where we see a concentration of people holidaying, it appears that the accommodation providers have gone to some lengths to make sure that people have been secure."
Mr McCully said more than four thousand people have been in evacuation centres in Fiji, and a number of New Zealanders will be amongst them.
Read more:
Ships grounded, trees and homes blown away
Samoans in NZ anxious for news
* The New Zealand Red Cross will today deploy a team to Samoa to assist the Samoan Red Cross. You can donate to their Pacific Disaster Response Fund here.
- nzherald.co.nz, APNZ, NZ Herald, Newstalk ZB