Foreign Minister Marise Payne said Tonga had not requested an Australian medical assistance team following the natural disaster.
She said Tonga's strict border measures implemented due to COVID could make it more difficult for international assistance to get on the ground.
"It is a COVID-free country as far as I'm aware and that does complicate the movement of people as well," Senator Payne told reporters on Monday.
"If we do need to send a (medical assistance) team to Tonga for any reason, I have no doubt there would be there same level of positive volunteering I have seen right throughout COVID as well."
Since the start of the pandemic, there has been just one confirmed case of COVID-19 in Tonga.
It comes as Australia sent a P-8 plane to assess the damage following the natural disaster on Saturday.
The flight arrived in Tonga on Monday morning, with crews checking for damage to critical infrastructure.
Communications to the country have largely been disrupted following the tsunami.
The tsunami was caused by an underwater volcanic eruption, with the volcanic ash cloud also leading to flight disruptions in Australia.
An Aircalin flight from Narita in Japan to La Tontouta in New Caledonia was diverted to Brisbane overnight due to the volcanic disruption.
All passengers and crew from the flight spent the night in quarantine hotels, with a new flight time yet to be set.
Two Fiji Airways flights from Brisbane to Nadi were also cancelled on Monday due to the volcanic cloud.
It also also led to delays for flights to Townsville from both Brisbane and Sydney.
Prime Minister Scott Morrison said the communication disruption and ash clouds made the situation challenging.
"We're working to get as much support to Tonga as we possibly can," he told 2GB on Monday.
"They're part of our Pacific family, and ... like all of those island nations, we're always there to support and we certainly will be on this occasion."
All Australians and other officials in Tonga have been accounted for.
Senator Payne said the government was in contact with the high commissioner in Tonga, but communication was limited.
"This is a very challenging time. Communications are deeply, deeply affected by the events of the volcanic eruption. It has been felt in other parts of the region," she told reporters on Monday.
"We're seeking further information about the extent of the damage outside of (the capital) Nuku'alofa."
Defence forces and foreign affairs officials will be working with other countries in the region to provide support.
Pacific Minister Zed Seselja said while there were reports of significant property damage in Tonga, there have been no reports of mass casualties.
"There is still very limited, if any, information coming from the outer islands, and so that will be the focus in coming hours," Senator Seselja told ABC TV.
"We hope that in the next several hours, we'll have a much better assessment of the damage in those outer islands where communications continue to be cut off."
Senator Seselja said other support measures were being prepared and ready to go, including a C-130 plane with humanitarian supplies.
HMAS Adelaide, currently in Sydney, is being deployed to Brisbane where it will be loaded with supplies for Tonga.
He said there were some predeployed emergency supplies in Tonga.
