West Australian Premier Mark McGowan has praised his South Australian counterpart and taken aim at "appalling" criticism from the Morrison government amid continued debate about COVID-19 state border closures.
Mr McGowan has moved swiftly to close the border to SA following an outbreak of 20 cases linked to a hotel quarantine worker in Adelaide.
Queensland, Tasmania and the Northern Territory have also shut their borders in a move criticised by federal Liberals.
WA's Labor premier on Tuesday applauded SA leader Steven Marshall's push to eliminate the virus by reimposing restrictions on gatherings and public activities, saying it would save lives and leave the country better off.
He said the criticism levelled at Daniel Andrews during Victoria's recent lockdown had been outrageous, singling out federal Treasurer Josh Frydenberg who had accused officials of "callous indifference" to job losses.
"Some of those ministers, Mr Frydenberg and some of those characters, their behaviour was appalling," Mr McGowan said.
"Dan Andrews did what he had to do ... the fact they undermined, criticised and attacked the whole way along during a period of extreme pressure was appalling.
"Steven Marshall has done the right thing and I support him in what he's doing. I'd urge everyone to support him in what he's doing."
Mr McGowan also took aim at the federal government's "artificial" Christmas deadline for reopening all state borders, saying it didn't make any sense.
A total of 185 passengers arrived at Perth Airport on Monday on two flights from Adelaide and were met by police upon arrival.
All have been tested for COVID-19 and are awaiting results.
"We know there is a very low risk of anyone being positive but we are being absolutely and completely cautious," Mr McGowan said.
A further two flights are scheduled to arrive from Adelaide on Tuesday, with passengers only able to board if they can meet strict exemption criteria.
Exempt travellers include government officials, military personnel, transport, freight or logistics workers and people allowed in on compassionate grounds.
Similar rules will come into effect at the Eucla checkpoint on the SA-WA border from Wednesday evening.
SA recorded just three new cases on Tuesday, all linked to the same family cluster, but Mr McGowan has warned any continued escalation could lead to the hard border restrictions returning for all states and territories.
WA recorded no new cases overnight. The state has 12 active cases, all returned overseas travellers in hotel quarantine.