Minister for Foreign Affairs Marise Payne said Australia was working closely with the Tongan government after the eruption of an underwater volcano on Saturday.
Senator Payne announced a Royal Australian Air Force aircraft had been deployed to conduct an assessment of damage to critical infrastructure, which will determine the next phase of the response effort.
"Today we have been able to deploy a Royal Australian Air Force P8-A Poseidon Aircraft to undertake surveillance activity over the affected area, working very closely with New Zealand to work on that surveillance," she told reporters during a visit to Nowra on Monday.
The Joint Australian Tsunami Warning Centre issued a tsunami warning for the NSW coast, and caused Shoalhaven beaches to close, following the eruption on Saturday, January 15.
The warning has since was cancelled by the centre late Sunday night.
Senator Payne said Australia was working closely with the government of Tonga but communications were very restricted.
"We will be working closely with the Government of Tonga, with Her Royal Highness and the High Commissioner of Tonga in Canberra, to ensure that we are able to deliver the sort of support that we provide to our Pacific family and our Pacific friends," she said.
"This is a very challenging time.
Communications are deeply, deeply affected by the events of the volcanic eruption.- Senator Marise Payne, Minister for Foreign Affairs
"We'll continue to work through the Department of Foreign Affairs and Trade, myself and the Minister of International Development and the Pacific Senator Zed Seselja to ensure that we are providing all the support that Australia possibly can."
Senator Payne encouraged Australian's with relatives in Tonga to call 1300 555 135 and from overseas, +61 262 613 305.
"Those numbers for consular support if you have concerns about Australian family members in Tonga who you may not have been able to make contact and for family members for whom you may have concerns over," she said.
Sign up for our newsletter to stay up to date.