Was the island of Tonga completely wiped out by the eruption?
A thick layer of ash covering entire communities can be seen in the first images of devastated Tonga to emerge after what experts believe is the world's largest volcanic eruption in more than 30 years.
This is how the Tonga volcano shock wave spread 0:45
How is and where is Tonga, the country affected by the eruption of an underwater volcano?
Aerial photographs released by the New Zealand Defense Force from the Ha'apai Islands in central Tonga show trees, houses and fields covered in gray ash, spewed by the underwater volcano Hunga-Tonga-Hunga-Ha'apai when it erupted on Saturday and generated tsunami waves that crashed into the Pacific.
Satellite images show a similar scene in the Kolofo'ou district of the capital, on the main island of Tonga, with trees and houses completely covered by volcanic debris.
Some buildings appear to have collapsed and aid workers are now concerned about water contamination and food security in the district.
BEFORE AND AFTER: Satellite images of the main port of Tonga's capital, Nuku'alofa, show the impact of the massive volcanic eruption and tsunami.
(Maxar Technologies via AP)
But as Tonga's first deaths from the natural disaster were confirmed and rescue operations continued, aid workers warned that the true scale of the destruction remains unknown.
Communications have been severely affected by the disaster, with some smaller islands completely cut off.
Alexander Matheou, director of the International Federation of Red Cross and Red Crescent Societies, said that in addition to the ash, there is "large-scale coastal damage as a result of the tsunami wave."
"We are especially concerned about those low-lying islands close to the eruption," he added.
"At the moment, we know very little."
The delivery of humanitarian aid to the country has been hampered by falling ash covering the capital's airport runway, according to officials from several donor countries.
Volcanologist explains underwater volcano eruption near Tonga 1:58
What are underwater volcanoes like the one that erupted in Tonga?
New Zealand will deploy two Royal Navy ships to the other Pacific island nation on Tuesday, the country's defense minister, Peeni Henare, said in a statement.
He added that it would take three days to reach Tonga.
The two ships, including HMNZS Wellington and HMNZS Aotearoa, will carry a Seasprite helicopter as well as humanitarian and disaster relief supplies, Peeni said.
"Water is a top priority for Tonga at this stage and HMNZS Aotearoa can carry 250,000 liters and produce 70,000 liters per day through a desalination plant," he added.
An aerial view of a P-3K2 Orion surveillance flight shows heavy ash fall in Nomuka, Tonga, on January 17, 2022.
Significant damage has been reported in Tonga, which is home to more than 100,000 people, the majority on the main island of Tongatapu.
At least 100 homes across the archipelago have been damaged, with at least 50 completely destroyed, according to Save the Children Fiji Executive Director Shairana Ali.
But the numbers are likely to rise as rescuers manage to restore lines of communication, he added.
Volcano eruption near Tonga probably won't be large enough to affect global climate, experts say
"This is a very unique type of crisis that we are facing because of a lack of communication... the biggest challenge right now is getting detailed information from the authorities and from Tonga," Ali said.
And he added that they expect to see water shortages in the coming days.
A key undersea communication cable connecting Tonga to Fiji is damaged and repairs are not expected to begin until February 1.
"This cable is vitally important to Tonga for all of its digital connectivity with the rest of the world," Southern Cross Cables chief technology officer and vice president of operations Dean Veverka said on Tuesday.
From space, the moment before the Tonga disaster 0:42
Deaths in Tonga
At least two people, including a British citizen, have died in Tonga after tsunami waves crashed onto roads, inundating residential communities and causing power outages.
The 13 deadliest tsunamis in history
The body of British woman Angela Glover was found after she was swept away by the tsunami, her brother, Nick Eleini, said in a statement on Monday.
Glover, 50, who lived in the capital Nuku'alofa with her husband and ran an animal welfare charity, was trying to rescue her dogs when the waves hit, Eleini said.
The eruption of an undersea volcano off Tonga, triggering a tsunami warning for several South Pacific island nations, is seen in a satellite image taken on January 15, 2022.
"Angela's dream was always to swim with whales, and Tonga gave her the opportunity to fulfill these dreams," Eleini said.
Saturday's eruption of the Hunga Tonga-Hunga Ha'apai volcano was probably the largest volcanic event on record since the eruption of Mount Pinatubo in the Philippines in 1991, according to experts.
Huge volcano eruption in Tonga was a once-in-a-millennium event
Photos and videos posted on social media immediately after the event showed people fleeing from the tsunami and the sky darkened by the cloud of ash.
Boats and large rocks were washed ashore in Nuku'alofa, while along the coast several businesses were damaged.
Tsunami waves were felt thousands of miles away in Hawaii, Japan and along the west coast of the United States.
At least two people died in Peru from "atypical waves," the Peruvian National Police reported this Sunday.
The volcano sits in the seismically active Pacific Ring of Fire and is about 65 kilometers (40 miles) north of Tonga's capital.
It had been active since December 20, but was declared inactive on January 11, according to CNN affiliate Radio New Zealand.
CNN's Elizabeth Yee contributed to this story
CNN's Elizabeth Yee contributed to this story