Prime Minister Scott Morrison says he will restrict overseas arrivals, with a plan to go to the national cabinet on Friday.
NSW and Victoria had done the heavy lifting on quarantining international arrivals, and with international flights no longer landing in Melbourne, flights had been diverted to other cities, he said.
"I'll be taking a proposal to national cabinet to slow that down," he said.
Western Australia has called for lower arrivals in that state, but Mr Morrison said there was no strong case for Western Australia to take fewer. Each state should carry a share, he said.
"The issue is the overall level of returning Australians are and that's why I'll be bringing a proposal on Friday to reduce the load," he said.
"At this time we don't want to put any more pressure on the system than is absolutely necessary."
On March 20, the borders were closed to non-Australians Compulsory hotel quarantine began on March 28. From March 21 to June 30, more than 212,000 people had flown into Australia, the Border Force said. The number included air crew. The Border Force is yet to provide figures on numbers that have been through hotel quarantine.
But Mr Morrison said he Victorian lockdown had not changed his view that internal borders should remain open.
"Victoria has self isolated," he said. "My view about people moving from NSW to Queensland, or to South Australia or Western Australia has not changed...
"This is about Victoria isolating itself, not other states shutting themselves off to Victoria. There's a key difference in that."
He called on people who live in and around the NSW-Victorian border towns to stay put and not travel.
NSW Premier Gladys Berejiklian said the NSW government was considering compulsory 14-day quarantine for people returning to that state from Melbourne.
And she also asked people in Wagga not to visit border communities, and asked people who live in border communities not to leave their area. She warned that if they didn't heed the message, NSW would take stronger action.
More to come