The Deputy Chief Medical Officer Paul Kelly is confident Chinese authorities will approve a second Qantas airlift of Australians from the coronavirus epicentre of Wuhan.
The plane, which was originally scheduled to leave Wuhan on Friday night, did not get the go-ahead to land from China.
The ABC reports the Qantas flight is now scheduled to leave Wuhan at 3.15am (AEDT) on Sunday once it gets approval.
Professor Kelly said Australia is working with Chinese authorities to get clearance "as soon as possible".
Asked whether he was confident of an airlift, he told reporters on Saturday: "Yes, I am confident, but I can't absolutely guarantee it because it is indeed on Chinese soil."
The Qantas flight in presently in Hong Kong.
"Many flights out of Wuhan have been delayed," a spokesperson for the Department of Foreign Affairs and Trade told AAP.
This will be the second evacuation flight to get Australians out of China.
The second group will be quarantined at an old mining camp near Darwin.
"We are in contact with all passengers on the manifest about the status of the flight," the DFAT spokesperson said.
"The assisted departure is a complex operation under difficult circumstances. Any such departure is always subject to operational requirements and to Chinese government final approval."
Once the Australians are extracted they will be sent to the Manigurr-ma Village at Howard Springs, 30km from Darwin, with Christmas Island unable to house another couple of hundred evacuees.
The federal government said on Friday evacuees would be screened before boarding the plane in China and continuously monitored by medical staff during the flight.
Anyone found to be unwell on arrival at Darwin will be taken directly to hospital where they will be quarantined, the government said.
Prime Minister Scott Morrison has warned people not to assume any further evacuation flights will be possible, either from Wuhan or mainland China.
Australia has so far had 15 confirmed coronavirus cases: five in Queensland, four each in NSW and Victoria and two in South Australia.
Australian Associated Press