Police say no survivors are expected to be found on Whakaari/White Island after Monday's volcanic eruption.
Twenty-three people were rescued from the island off the Bay of Plenty coast - five later died from their injuries.
Police estimated up to 27 people had been left stranded on the island when rescue efforts were abandoned because of safety concerns.
Late last night they said they were still working to confirm the exact number.
Their grim conclusion that no one is still alive came after the police Eagle helicopter, rescue helicopters and Air Force craft flew reconnaissance flights over the island and reported no signs of life.
A navy ship was due in the area at dawn this morning to deploy drones and other observational equipment.
The police disaster identification team is assembling in Whakatāne.
Police say New Zealanders and foreign tourists are thought to have died in the disaster - many of the tourists were passengers on the cruise ship Ovation of the Seas, currently berthed in Tauranga.
The ship's operator, Royal Caribbean, issued a statement saying it is devastated by the events.
It says it's providing all the help and care it can to its guests and their families, including offering medical resources and counselling.
White Island Tours had a party on the island when it erupted.
Its chairman Paul Quinn says: "Devastation is an understatement. This is a terrible tragedy and our thoughts and prayers are with everyone who has been impacted".
He says his staff and their families are showing immense strength and courage in the wake of the tragedy.
Former Whakatane mayor Tony Bonne has confirmed one of the company's guides, who he knew personally, is among the dead.
The Police and Prime Minister Jacinda Ardern are due to hold a media conference at 7am.