Two air force planes carrying humanitarian supplies are ready to depart Australia for Tonga on Thursday as soon as conditions allow, with the ash-covered airport runway expected to be cleared soon.
The extent of the devastation wrought by the eruption of an underground volcano and subsequent tsunami on the Pacific nation is yet to be fully realised with communication systems down and ash preventing humanitarian relief from landing.
Prime Minister Scott Morrison spoke with his counterpart Siaosi Sovaleni on Wednesday afternoon and said Australia's priority remained delivering assistance in a COVID-free manner.
"I reassured him that Australia stands shoulder to shoulder with the Kingdom of Tonga as it responds to the undersea volcanic eruption and tsunami," Mr Morrison said.
"I conveyed Australia's deep sadness for the loss of life and the damage caused by the disaster, and wished those injured a speedy recovery."
Australian and New Zealand have sent surveillance flights in the past two days to survey the damage.
HMAS Adelaide arrived in Brisbane on Wednesday to be loaded with humanitarian and disaster relief supplies, along with critical equipment to help recovery efforts.
It's expected the voyage to Tonga will take five days, and the ship will serve as a base for relief work.
Tonga has also approved the arrival of HMNZS Wellington and HMNZS Aotearoa which departed New Zealand on Tuesday and are expected to arrive on Friday.
Australia has committed $1 million towards Tonga's recovery effort.
Mr Sovaleni has met with the heads of each diplomatic mission in the country to discuss support options.
Mr Morrison said the Australian High Commission in Nuku'alofa is in close contact with the Tongan government "to ensure our relief efforts best meet the country's immediate needs".
"The government is also engaged with the many Tongans living in Australia to provide information and support," he said.
Power has been restored but communication in and out of the country remains difficult after a key underwater cable was damaged.
Telstra is working with Digicel Pacific to find a satellite communications solution while the Australian mission will also help repair the damaged underwater telecommunication cables and set up a temporary satellite system.
But New Zealand's foreign ministry says US cable company SubCom advises it will take up to a month to repair the damaged cable.
One Tongan academic at the Australian National University said a lack of clear information is hampering recovery efforts.
Researcher Gemma Malungahu, who has family in Tonga, said information about the safety of people in the country remained unclear.
"The only communication lines open are those from the High Commission in Australia and New Zealand, but there has been no communication made with family and friends," Dr Malungahu said.
The death toll from the underwater volcanic eruption and tsunami remains at three.
In its first official statement published on Tuesday night, Tonga's government called the tsunami an "unprecedented disaster", with communications heavily impacted in the country.
Red Cross head of programs for the Pacific Sainiana Rokovucago said supplies had been secured for 1200 affected households.
"We're seeing on the island the need for assistance with safe and clean drinking water due to saltwater flooding and widespread ash from the eruption and we really need containers for water."
Australian Associated Press