Department of Foreign Affairs and Trade official Fiona Webster says 27,000 Australians have registered overseas, with 18,800 of them wanting to come home.

Most were in India, the Philippines, South Africa and Vietnam, she said on Thursday.

More than 371,000 Australians have returned home since March 13, when the public was urged not to go overseas because of the coronavirus health crisis.

The federal government has organised 64 repatriation flights home, with 13 of those from India.

Dr Webster said limits on international arrivals posed a "significant challenge" for Australians overseas.

"We can only work within the quarantine capacity," she said.

DFAT has tried to help vulnerable Australians or those in exceptional circumstances, but had limited sway with airlines, she added.

Nearly 400 people have been given emergency loans to help cover the cost of airfares home.

States requested limits on international arrivals so hotels could cope with the mandatory two-week quarantine program.

The current limits will remain in place until at least October 24.

Deputy Chief Medical Officer Michael Kidd said the government's expert medical panel didn't provide advice on arrival caps.

"These are determinations being made by each state and territory based on what they feel is a safe number of people able to come into the country and be monitored and supported in hotel quarantine," he told reporters in Canberra.

"We are aware that there are many Australians who do wish to return to the country, to return to their families."

Until October 24 the limits are:

* Melbourne: no international passenger arrivals

* Sydney: 350 passenger arrivals per day

* Perth: 525 per week

* Brisbane: 500 per week

* Adelaide: 500 per week

* Canberra and Darwin: limits discussed with jurisdictions on a case-by-case basis

* Hobart: no international flights

Australian Associated Press