Prime Minister Jacinda Ardern says New Zealand is ready to help the people of Tonga, as a reconnaissance plane is due to arrive shortly.
Ardern, joined by Minister of Defence Peeni Henare, told media that the arrival of a Royal NZ Air Force Orion in Tonga is now imminent.
She also acknowledged that supplies are ready to go - no matter what the status of the main airport in Tonga is.
On the Tonga Hunga Tonga-Hunga Haʻapai eruption, Ardern said an Air Force Lockheed C-130 would be dispatched. Another aircraft, a P-3K2 Orion, was already monitoring the situation.
"What the Orion is doing is reconnaissance," she said.
Henare said it was important to ensure any vessels or craft deployed would need to have contact with authorities in Tonga.
Ardern said they have been communicating with people using satellite phones and information from people on the ground through other avenues - including via church ministers and familial links.
"We are getting back critical information that's helping with the planning."
The stand-up comes as the Government waits to get word on the extent of the damage caused by a giant volcano eruption late on Saturday afternoon, which resulted in tsunami waves wiping out homes on the coast and sending locals to higher ground.
A Royal NZ Air Force Orion aircraft left for Tonga early this morning and is due to send back images and video footage of the damage.
Crew members will assess the situation and determine exactly what help is needed, initially.
The situation has been hampered by the fact that communications networks in the island nation have been cut for close to 40 hours since the eruption and Tongans from around the world have struggled to make contact with loved ones back home.
Those who have managed to get word out via social media messages on Facebook, Twitter or Viber have said there have been no reports of loss of life.
However, so far, there has been no contact with those living on the outer islands closest to the volcano.
Among the New Zealand-based Tongans trying to get in contact with families back in the islands is Auckland Tongan community leader Salote Heleta-Lilo.
She told the Herald they were still trying desperately to get news from her sister who lives at the family home in Nuku'alofa and takes care of an elderly uncle, who is paralysed.
'I can't sleep properly. You go to sleep thinking of them'
"It's a concern because they're right on the coast there. It's quite sad - living in fear and not knowing what's happened in Tonga," she said.
Heleta-Lilo said she believed their house will be severely damaged if not destroyed as a result. But that was not the main worry at the moment.
"The house is materialistic. I'm just concerned for their lives.
"I can't sleep properly. You go to sleep just thinking of them."
Heleta-Lilo, who was born and raised in Tonga, said she had never seen anything like the eruption in her lifetime.
Speaking to a cousin in Hawaii yesterday, she was shocked to hear him describe rocks raining from the sky after the eruption.
"He said there were little stones raining outside. That's how scary it is - it shows how big it was."
Ash cloud spreads to Fiji, New Caledonia, Vanuatu and Samoa
MetService - one of nine Volcanic Ash Advisory Centres around the world - is monitoring the ash movement across the Pacific region.
Its role is to provide accurate and up-to-date information for aircraft and airlines to ensure safe operations after such an eruption.
Meteorologist Luis Fernandes told the Herald they were in direct contact with the Orion that left for Tonga earlier this morning - to ensure they would be able to fly in safely.
He said the ash had mostly dispersed in the last almost 48 hours since the eruption and had spread to other Pasifika countries.
Current imagery showed ash covering the whole of Tonga and is now affecting parts of Fiji, New Caledonia, Vanuatu and Samoa.
At this stage, it did not look as if it will reach New Zealand, Fernandes said.