Australians and officials living in Tonga have all been accounted for in the wake of the tsunami that struck the country after a nearby underwater volcano eruption.
But Minister for the Pacific Zed Seselja says it is a rapid unfolding situation with communications having been significantly impacted.
"We have no particular concerns about Australians at this stage ... that's subject to some communications difficulties," Mr Seseja told reporters in Canberra on Sunday.
He said Prime Minister Scott Morrison had spoken with his New Zealand counterpart Jacinda Ardern earlier on Sunday to put in place a coordinated response.
He said both countries are sending surveillance aircraft to help gather as much information as possible on the situation.
Australia will aim to send its plane on Monday to reach Tongan airspace by 9am.
"This is subject to weather conditions, particularly issues around the ash cloud. There are no guarantee we will be taking off tomorrow morning," the minister said.
Australia is also preparing for humanitarian assistance though a flight from Brisbane which should be ready to go on Monday, but again subject to flight conditions and the ability to get on the ground.
The Bureau of Meteorology said the Hunga Tonga-Hunga Ha'apai volcano erupted at 3.10pm AEDT on Saturday, and tsunami waves have been observed as a result of the eruption.
The bureau said a tsunami wave height of 1.27 metres was observed on Norfolk Island at 9pm AEDT and an 82cm wave was registered on the Gold Coast at 10.54pm AEDT on Saturday.
Waves up to 1.10m-high were being recorded at Ned's Beach on Lord Howe Island about 11pm AEDT and a 50cm surge was observed at Hobart's Derwent Park about 11.44pm AEDT.
Port Kembla in NSW's Wollongong registered a 65cm wave at 2.50am AEDT on Sunday.
Countries around the Pacific were also on alert, with residents in parts of Japan advised to evacuate after waves of more than a metre.
The bureau earlier detected a 1.19m wave in Nuku'alofa, Tonga's capital.
Land warnings were issued earlier for Norfolk Island and Lord Howe Island, however by 10.30am on Sunday these were downgraded and replaced with marine warnings.
"In areas with a threat to the marine environment only, emergency authorities advise people to get out of the water and move away from the immediate water's edge of harbours, coastal estuaries, rock platforms and beaches," the bureau said in a statement.
The marine warnings remain for the two islands and coastal areas of NSW.
Tsunami warnings for Macquarie Island and coastal areas of Queensland, Victoria and Tasmania were cancelled on Sunday morning.
Australian Associated Press
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