SYDNEY (AFP) - Australia will lift a ban on citizens travelling overseas without permission, the government announced on Wednesday (Oct 27), with the country's border set to open to skilled workers and international students by year's end.

More than 18 months after Australia closed its international borders, fully vaccinated citizens will no longer have to seek an exemption to leave the country, a joint statement from the health and home affairs ministries said.

It comes as the country's adult double-dose vaccination rate edged closer to an 80 per cent target.

Home Affairs Minister Karen Andrews said that while Australian citizens were currently being prioritised, more travel restrictions - including for some non-citizens - would be eased as vaccination rates increased.

"Before the end of the year, we anticipate welcoming fully vaccinated skilled workers and international students," she said.

Prime Minister Scott Morrison, who foreshadowed the changes earlier this month, said Australia was now very close to announcing a reciprocal travel bubble with Singapore, which announced late on Tuesday that Australians no longer had to quarantine on arrival.

Qantas flights to Singapore are scheduled to resume on Nov 22.

Singapore Airlines said it would be expanding capacity to Sydney, with the Airbus A380 returning to the city on Dec 1.

"We're working to a timetable around about then which will see other visa-holders - in addition to Australians returning or going to Singapore and returning who are double vaccinated - being able to come to Australia," Mr Morrison told Channel 7 television.

On March 20 last year, Australia introduced some of the world's toughest border restrictions in response to the coronavirus pandemic.

For almost 600 days, countless international flights have been grounded, and overseas travel has slowed to a trickle.

Families have been split across continents, tens of thousands of nationals were stranded overseas and foreign residents were stuck in the country unable to see friends or relatives.

Quarantine arrangements for returning vaccinated residents will depend on where they arrive in Australia.

While Sydney has scrapped quarantine for returning travellers, other Australian states with lower vaccination rates still have mandatory and costly 14-day hotel quarantine requirements.

On Wednesday, Australia authorised booster shots of Covid-19 vaccines for people aged above 18 years, with the third dose expected to be offered to the entire population from next month.

The Therapeutic Goods Administration regulatory authority said it had granted provisional approval for one dose of the Pfizer-BioNTech vaccine to be given as a booster shot to adults.

"The provisional approval means that individuals aged 18 years and older may receive a booster (third dose), at least six months after the completion of a Covid-19 vaccine primary series," the agency said.

Health Minister Greg Hunt said a population-wide booster programme would begin no later than Nov 8, subject to approval from the nation's immunisation advisory body.

"We will commence with aged care and disability as a priority," he told reporters in Canberra.

Mr Hunt said the universal booster would be available to anyone who had received two doses of either the Pfizer-BioNTech, Oxford-AstraZeneca or Moderna vaccine.

Booster shots had already been made available to severely immunocompromised people earlier in October.

The government said it expected Moderna would also apply to Australia's medical regulator for booster shot approval.