Prime Minister Chris Hipkins says it has been "a very big night for New Zealanders", particularly in the upper North Island.
Hipkins gave an update hours after the government declared a national state of emergency over Cyclone Gabrielle.
It is only the third time in New Zealand's history an event has met the national state of emergency criteria, following the Christchurch earthquake in 2011 and Covid-19.
Limited communications
"A lot of families displaced, a lot of homes without power, extensive damage done across the country.
"Overnight it's difficult in the dark to find out exactly what's happening. At first light this morning as soon as the extent of the disruption and the damage became clear, advice was provided to the minister and therefore through the minister to me that a state of national emergency should be declared and we acted on that immediately."
He says government will be working as quickly as possible with agencies and telecommunications companies to restore communication.
Hipkins also thanks first responders and says the volunteer response across the country has been phenomenal.
"I had the opportunity to speak just before with some of the families from Muriwai who were evacuated in the middle of the night, they were indicating they had felt incredibly well supported.
"We'll continue to work with those community groups to make sure that we're providing them with as much support as we can so that they can provide support to the communities that have been affected."
Hipkins says one of the challenges with Gisborne at the moment is limited communications.
"That has proven to be very difficult in the last few hours."
There will be an opportunity for the government to have a good look at the situation with the slash, he says.
Hipkins says he hopes to get back to Wellington today, and has had a briefing from the team at National Emergency Management Agency (NEMA).
The defence force is on the ground, providing logistical support, helping with evacuations, and moving supplies. They will help with the clean-up as appropriate "when we get to that point", he says.
"This extreme weather event ... probably the biggest we have seen in recent times comes hot on the heels of other extreme weather events that we have seen.
"It is a particularly tiring time, a particularly stressful time, so I want to again on behalf of all New Zealanders reiterate out thanks to all those who are working around the clock for those who need that extra support."
Natural and Built Environments bill
Hipkins says the Natural and Built Environments bill before Parliament - the main replacement legislation for the RMA - will have an effect on where houses are built.
"That will place a much greater emphasis on natural hazards when it comes to things like deciding where we build. That is something where I think we've got a long history of perhaps poor past decisions in New Zealand that we're confronting right now. It's not that helpful for people who are up to their waists in water to be having that debate right now but it is one we need to have as a country."
"All of the other things as a country we've dealt with over the last few years ... the last decade and a half or so we've had everything from earthquakes, natural disasters, volcanic eruptions, weather events. It is a lot, and for some people those things accumulate and the mental health impact could be a significant one.
"We're very aware of that as a government and we'll be making sure we provide as much mental health support as we can."
Families in financial distress
Hipkins says a lot of families are already in financial distress.
"It'll take us a few days to really get a handle on how many families have been affected by these extra events over the last few days when it comes to the extreme weather. That will include working with insurance companies and relevant community agencies to support the most vulnerable," he says.
"We'll make sure we're getting energy to where it's most needed, most urgently."
Hipkins says he had a pre-arranged call with British Prime Minister Rishi Sunak this morning and the first thing they spoke of was the cyclone, and the UK's support to the people of New Zealand.
Hipkins says the recovery effort will be front and centre for the government's programme over the next weeks and months.
"We know that this won't be an overnight recovery, it's going to take a while, some people will be displaced from their homes for an extended period ... businesses will continue to feel the tail of this for some time and we'll need to support them through that as well."
He says having spoken to some of the evacuees at the Trusts Stadium where the briefing is being held, many were feeling supported but did not get much sleep last night.
"They're feeling very well cared for but of course they're displaced... I think people generally accept that this is an extreme weather event."
"Like it or not you can have the best technology in the world but until the sun comes up and you can actually see what's going on, there's a limited amount that you can actually do and know overnight."
He says the winds are very strong and that will probably be limiting the amount of support that can be provided by air.
The defence force is providing support by land and by sea, he says.
Parliament's business committee will be deciding in a meeting about lunchtime how the event affects Parliament's sitting schedule.
On Princess Anne's visit to New Zealand, Hipkins says he welcomes her despite the extreme weather. He had been planning to meet with her but those plans may be affected, he says.
'I would ask all businesses to be responsible'
Hipkins asks all employers to be responsible in what they are asking of staff.
"There are some essential businesses that will be asking their staff to come back to work including so that they can keep essential supply lines open, food for example - people need to continue to be able to buy food - so those decisions are best made by businesses but I would ask all businesses to be responsible."
Follow the latest with live updates in RNZ's live blog.
Read more:
- Cyclone Gabrielle: What the national state of emergency means
- Cyclone Gabrielle: Flooding and land slips isolate some Auckland regions
- Firefighters trapped, injured in Auckland's Muriwai house collapse
- By the numbers: Cyclone Gabrielle's impact
- Cyclone Gabrielle: Who to call, what to do if the roof comes off or windows smash
National state of emergency: What you need to know
- The New Zealand government has declared a National State of Emergency, to assist in the response to Cyclone Gabrielle.
- The declaration will apply to the six regions that have already declared a local State of Emergency: Northland, Auckland, Tairāwhiti, Bay of Plenty, Waikato, and Hawke's Bay.
- A national state of emergency gives the national controller legal authority to apply further resources across the country and set priorities in support of a national level response.
National Emergency Management Agency advice:
- Put safety first. Don't take any chances. Act quickly if you see rising water. Floods and flash floods can happen quickly. If you see rising water do not wait for official warnings. Head for higher ground and stay away from floodwater.
- Stay at home if it is safe to do so. But have an evacuation plan in case your home becomes unsafe to stay in.
- If you have evacuated, please stay where you are until you are given the all-clear to go home.
- People should stay up to date with the forecasts from MetService and continue to follow the advice of Civil Defence and emergency services.
- Do not try to walk, play, swim, or drive in floodwater: even water just 15 centimetres deep can sweep you off your feet, and half a metre of water will carry away most vehicles. Flood water is often contaminated and can make you sick.