A group of 34 women and children tried to leave the Al Roj refugee camp in Syria on Monday local time, planning to travel to the capital Damascus and fly to Australia.
But they were sent back to the camp because of an administrative issue, a Syrian official told Reuters.
Prime Minister Anthony Albanese said the government would not provide any assistance to the group beyond what is legally required, and warned they could face criminal charges if they do return.
"My mother would have said, 'If you make your bed, you lie in it'," he told ABC TV on Tuesday.
"If there are any breaches of the law, they will face the full force of the Australian law if they come back."
The group of Australian citizens is believed to be made up of the partners and children of former Islamic State fighters, who travelled to the Middle East to fight for the caliphate before it was toppled by US forces.
Since 2019, the women and children have been living in Syrian refugee camps and prisons.
Some of the women - known informally as ISIS brides - have claimed they were coerced into leaving Australia.
Government officials have long said they cannot stop Australian citizens from returning home of their own accord, and are obliged to provide them with passports if they can get to an Australian consulate or embassy.
But opposition senator Jonno Duniam said the government should do all it can to prevent the group entering Australia while they pose a risk.
"The ISIS brides cohort are a group who have followed or have been forced to relocate to Syria alongside their ISIS fighter husbands," he said in a statement.
"These are people who have been part of a group that want to attack our way of life and are a very serious risk to our society."
Senator Duniam said the government should consider issuing temporary exclusion orders, which allow it to bar people from returning to Australia if they present a security risk.
UN special rapporteur on human rights and counter-terrorism Ben Saul disagreed, arguing it would be "really irresponsible" to stop Australian citizens from returning home, warning the group is acutely vulnerable in Syrian camps.
"It's not the job of Syria to indefinitely host Australians who Australia won't let come home," he told AAP.
"If you genuinely believe individuals are a security risk, then Australia should deal with that. It should prosecute them. It should apply control orders to them. If people are terrorists, it shouldn't just let them loose on the world, in Syria or Iraq or other countries, to pose threats there.
"These are Australians. Australia created this problem. Australia needs to deal with it."
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