West Australian Premier Mark McGowan will seek urgent advice about a potential influx of travellers scrambling to return home from Bali.
Australians in Indonesia face fines from Thursday after the nation's immigration authority announced it will not automatically extend expired visas or stay permits.
The Department of Foreign Affairs and Trade's Smart Traveller website warns flights to Australia are very limited and those who overstay permits could also face detention or deportation.
Coronavirus is widespread in Indonesia, the website adds.
It is unclear what impact the potential influx of returned travellers will mean for existing caps on international arrivals.
Perth Airport is currently limited to taking about 525 international passengers per week.
Mr McGowan said on Monday he hadn't been contacted about the issue but would seek urgent advice from the Commonwealth.
"We have to cope with large numbers of people still coming into the country. At any given point in time we have between 1200 and 1500 people in quarantine hotels," he said.
"What we don't want to have happen is problems in running those as they've had in Victoria, and that's really a numbers game."
Federal Health Minister Greg Hunt said it was up to the states and territories to determine whether they were able to accept more returned travellers.
"They've been very careful in their assessments and I think it's important that they are careful and will be guided by their honest judgment as to their safe capacity," he said.
The premier said he hoped legislation allowing the state to charge returned travellers for hotel quarantine would pass through parliament this week.
It will be retrospective to July 17.
"People have now had six months to come home," he said.
"There's a limited set of exemptions in hardship cases. We expect there'll be about 10 per cent of people eligible for that. But other than that, people will be paying."
Mr McGowan did not rule out a return to having people quarantine on Rottnest Island, saying it could be closed and repurposed within three days.
"Some of the health professionals don't particularly like Rottnest because it has some distance from the hospitals," he said.
"But my view is it's a great fallback option, particularly if we have a large number of people that we might not have expected come in from overseas."
Australian Associated Press