The Hunga Tonga-Hunga Ha'apai eruption - which could be the world's most powerful blast in three decades - caused a tsunami across the Pacific, and blanketed the Tongan capital Nuku'alofa in thick ash.
As of Monday morning, much of Tonga's power has been restored, as well as internal communication lines.
However, communication in and out of the remote Pacific nation remains limited, making both an assessment of local damage and the provision of aid dicfficult.
The United Nations has confirmed damage to buildings and infrastructure, as well as concerns over access to fresh water.
New Zealand Prime Minister Jacinda Ardern said boulders and boats had washed ashore on Tongatapu, the largest island and home to the capital, Nuku'alofa, around 65 kilometres south of the volcano.
"Seeing some of those waves come in and peeling back fencelines and structures, you can see the force of those surges," Prime Minister Jacinda Ardern said
"Everyone just wants to establish how wide scale that impact has been."
Tonga, with a population of 105,000, is comprised of 169 islands, a few dozen of which are inhabited.
NZ's Pacific Peoples Minister Aupito William Sio said key members of Tonga's royal family were safe and well.
"We want to be in Tonga and on the ground as soon as we are possible able to be," Ms Ardern said.
Volcanic ash in the air and on the runway in Tonga prevented an aerial mission in the immediate aftermath of the blast.
Just prior to 9am NZDT on Monday morning, a NZDF Orion aircraft took off from Auckland's Whenuapai base on a mission to investigate further.
An Australian P-8 Poseidon also left Brisbane on a similar mission.
"It's looking to provide an assessment of the outer islands in particular," Ms Ardern said.
Foreign Minister Nanaia Mahuta said New Zealand's High Commission in Tonga confirmed the flight would be safe to depart and land.
"Things are calm (but) there is significant ash fall," she told Radio NZ.
"80 per cent of power has been restored however internet connection and communications remain an issue."
New Zealand will follow the reconnaissance mission with flights from the heavy-duty Hercules C-130 to drop any needed provisions.
University of Auckland volcanologist Shane Cronin said the eruption was likely to be the world's biggest since the 1991 eruption of the Philippines' Mount Pinatubo.
"Our research into these earlier eruptions suggests this is one of the massive explosions the (Hunga Tonga-Hunga Ha'apai) volcano is capable of producing roughly every thousand years," he wrote in The Conversation.
"We found evidence of two huge past eruptions ... and then used radiocarbon dates to show that big caldera eruptions occur about ever 1000 years, with the last one at AD1100."
Aid agencies including Save the Children and Oxfam say they are ready to offer support.
Save The Children say all their staff and volunteers located in Tonga, Fiji and Vanuatu are safe and accounted for.
4°C