Western Australia will close three "high-risk" quarantine hotels and indefinitely reduce its returned traveller intake after a COVID-19 breach prompted a snap lockdown.
Premier Mark McGowan says the Mercure, Sheraton Four Points and Novotel Langley will stop taking guests from as early as mid-May.
"Whilst they are very secure, obviously they're not perfect, and the ventilation systems there we can't make perfect. So we're going to move out of those," he told reporters on Wednesday.
"That will result in a reduction in the number of people we can take into Western Australia. We'll work out what that is and how many we can take."
Two locally acquired infections were found after the virus leaked out of the Mercure hotel, plunging Perth and the Peel region into a long-weekend lockdown.
The government was aware of ventilation issues at the Mercure but had believed the risk could be mitigated.
WA on Wednesday recorded a third straight day of no new local cases but confirmed four cases in hotel quarantine.
Mr McGowan said he had advised Prime Minister Scott Morrison of the decision to retire the quarantine hotels.
"The prime minister was right when he said yesterday that our hotel quarantine system has been 99.99 per cent secure," he said.
"The problem with that 0.01 per cent is that the consequences can be dire. So that's why we're going to do everything we can to make sure we are as secure as possible in Western Australia."
Mr McGowan added that WA had been taking the highest number of returned travellers as a proportion of its population.
WA's cap on international arrivals is being halved to 512 a week for the next month.
The decision to close three of the 10 quarantine hotels will make it seemingly impossible for the cap to return to its previous level of 1025 a week.
Mr McGowan said the Novotel would accommodate a flightload of "low-risk" seasonal workers due to arrive from Tonga and Vanuatu next month.
The Sheraton Four Points was the site of a breach involving a security guard which led to an earlier lockdown in January.
A state quarantine advisory panel is looking at options for a purpose-built facility but Mr McGowan said he would prefer the Commonwealth take responsibility.
Authorities have identified 386 close contacts of confirmed cases from the latest lockdown and 367 have so far returned negative test results.
Interim restrictions remain in place in WA until 12.01am on Saturday, including the mandatory wearing of face masks and limits on gatherings
Some hospitality venues have opted to remain closed until restrictions are eased, with initial treasury estimates suggesting a $70 million hit to the economy.
Opposition Leader Mia Davies said the lockdown could have been avoided had the government acted on warnings about its quarantine hotels.
"The government has put families, communities and businesses at risk without warning and without compensation," she said.
The premier said he hoped the vaccination rollout would make lockdowns less necessary in the future.
Mr McGowan will get vaccinated next Monday when over-50s become eligible to receive the AstraZeneca jab at mass vaccination clinics across Perth.
GPs will be able to administer the jabs from May 17.