Australian Prime Minister Scott Morrison has back-tracked after suggesting vaccinations against the coronavirus could become mandatory.
Announcing a deal that could provide free doses to Australia's entire population, Mr Morrison had said there should only be medical exemptions.
But after concerns raised by health experts, he clarified: "There are no compulsory vaccines in Australia."
Meanwhile, visitors to Australia may also be required to have immunisation.
Health Minister Greg Hunt said he "wouldn't rule out" making it mandatory for anyone travelling to Australia - including Australians returning to the country - if that was the advice from medical experts.
"It would seem passing strange if we had a massive vaccination programme in Australia but we were then to allow people in who could bring it in," he told A Current Affair.
The Australian government announced it had signed a letter of intent with pharmaceutical company AstraZeneca and Oxford University, which is one of five coronavirus vaccine-makers to have reached an advanced stage of clinical trials.
Mr Morrison said if the trials were successful, he hoped the vaccine would be available early next year. "We will manufacture and supply vaccines straight away under our own steam and make it free for 25 million Australians," he said.
He told radio station 3AW that he expected it would be "as mandatory as you could possibly make it", though his government was still forming its policy. "There are always exemptions for any vaccine on medical grounds, but that should be the only basis.
"We are talking about a pandemic that has destroyed the global economy and taken the lives of hundreds of thousands all around the world, and over 430 Australians here."
The country would aim for 95% of the population to be vaccinated, he added.
Vaccinations are not mandatory in Australia. Behavioural scientist Julie Leask told the Sydney Morning Herald it was "premature and unhelpful" to talk about mandating a vaccine for Covid-19 "when we don't even have a vaccine that we know actually works", and she warned of a possible 'backlash'.
Mr Morrison, in clarifying his position later, told 2GB radio station there would be "no compulsory vaccine but there will be a lot of encouragement and measures to get as high a rate of acceptance as usual".
Mr Hunt said they hoped to encourage mass take up of the vaccine with a range of "incentives and encouragement".
The cost of supplying the vaccine to the whole population has not yet been fixed. Separately, Australia has also signed a deal worth A$25m with Becton Dickinson, an American pharmaceutical company, to supply 100 million needles and syringes.
Australia has recorded 450 coronavirus deaths, most from an outbreak in the state of Victoria.
Earlier this month, Victoria declared a state of disaster and imposed strict lockdown measures after a surge in infections.
It still has more than 7,000 active cases, but the number of new infections has declined in the past week.