Medics are being mobilised to fly to Christmas Island under the government's plan to get Aussies out of China and protect the mainland from the coronavirus.

A team of 24 medical professionals are bound for Christmas Island to deal with Australian coronavirus evacuees who face isolation in a bid to protect the mainland from the deadly disease.

The government is working to get Australians out of China and more than 600 Australian citizens in the epicentre province of Hubei have registered for advice or assistance.

But it's unclear how many will join what the government is calling a "humanitarian" mission to get people home and into quarantine and shield mainland Australians at the same time.

The executive director of the National Critical Care and Trauma Response Centre, Professor Len Notaras said the doctors, nurses and allied health officials being sent to Christmas Island were of the "highest calibre" and were being drawn from every state and territory.

They are all very experienced in dealing with potentially highly infective cases and will have access to all necessary equipment to care for critically-ill patients if necessary.

A demountable hospital will be set up including diagnostic and protective equipment and negative pressure facilities.

However, Prof Notaras told reporters in Darwin it was important to note those people who will be placed in isolation were not sick at this stage and would likely not become sick.

He said they would not be held in detention, although their movements would be restricted.

Should any begin to show symptoms or become seriously ill the medical team on the island would make the initial call on their continued treatment.

Anyone who became critically ill would likely be repatriated to Australia, possibly to WA or to a hospital close to where they live, Prof Notaras said.

Health Minister Greg Hunt said Australia's actions were driven by medical advice, and the World Health Organisation was strong in its support for quarantine measures to stem the spread of the virus.

"Our job is to protect Australians and provide support for citizens overseas and the best way to do that is to find a place which was designed to deal with people who were coming (from) overseas ... and to do that in a way which is humane," Mr Hunt said.

Home Affairs Minister Peter Dutton defended the Christmas Island plan, saying it would help keep Australia safe.

"I can't clear a hospital in Sydney or Melbourne to accommodate 600 people. We don't have a facility otherwise that can take this number of people," he told the Nine Network on Thursday.

Christmas Island administrator Natasha Griggs said residents had expressed some concerns but had been assured that all necessary measures had been put in place to ensure the safety of locals.

"By and large, the Christmas Island residents understand that this is a humanitarian mission and they're generally supportive," she said.

"We've got a fantastic team of people that have got experience in doing this, a track record of success so the residents of Christmas Island have no need to worry."

But Australian Medical Association boss Tony Bartone said there were better alternatives to sending evacuees to Christmas Island, with some medical specialists suggesting the Woodside army barracks near Adelaide and another facility just north of Katherine in the NT.

There are nine confirmed cases of the deadly virus in Australia. The second case in Queensland and third case in Victoria confirmed on Thursday evening as Chinese women visiting from Hubei.

Of the four cases in NSW, two have been discharged having been declared no longer infectious, while a Chinese man and woman in a tour group from Wuhan are in Gold Coast University hospital.

Authorities are trying to track down the other 171 passengers on the same Tiger Airways flight as the two Queensland cases.