“While the reduction of those caps will certainly—right across the system—obviously take some pressure off, as we have observed over the course of these past 18 months, that alone does not provide any fail safe regarding any potential breaches” of the virus into the community, Morrison told reporters in Canberra after a meeting with state and territory leaders on Friday.

In his first appearance after emerging from self-isolation in the wake of traveling to Europe last month to meet leaders attending the G-7 summit, Morrison said the leaders had also agreed to a pathway to switch from virus suppression to focus on reducing the risk of serious illness, depending on a high vaccination rate that’s yet to be determined.

Morrison’s move means that even as other developed economies such as the U.S. and the U.K. open up, Australia is further isolating after imposing strict border restrictions when the pandemic began 15 months ago. A tardy vaccination rate—the second-slowest among the 38 OECD nations—has made it particularly vulnerable to the delta variant, which is increasingly leaking out of the ad-hoc quarantine system for international arrivals.

The leaders of Victoria and Queensland states have been pushing for urgent cuts to the intake of arrivals, saying it’s allowing for too many non-Australian residents to enter the nation, sometimes with infections. That’s contributed to the lockdowns imposed in the past week in cities continent-wide, including Sydney, Brisbane and Perth; the current outbreaks are also linked to mining workers and airline crew who have traveled around the nation.

“My heart goes out to thousands of Australians who have to wait longer to come home,” New South Wales state Premier Gladys Berejiklian told reporters in Sydney.

Berejiklian has resisted new arrival caps, even as Australia’s most-populous city is in the midst of a two-week lockdown that may need to be extended, with cases rising by 31 infections on Friday from the previous day. “Just because you reduce the number of people coming in, doesn’t mean outbreaks aren’t going to happen.”

Government data shows that Australia had provisionally-estimated arrivals of 115,600 in May, up 60,800 from the previous month. The increase was mainly due to the start of a travel bubble with New Zealand in mid-April that has since been suspended due to the delta outbreaks.

Still, May 2021 arrivals plummeted 92.7% when compared with pre-pandemic levels two years earlier.

The snap lockdowns show the limits of Australia’s so-called “COVID-zero” strategy, which has relied on closed international borders and rigorous testing to eliminate community transmission of the virus. In contrast to the U.K. and U.S. which have had relatively strong vaccination rates, a slow rollout in Australia means the economy, and particularly domestic tourism, remains vulnerable.

The government’s vaccination program has been hit by supply-chain holdups from contracted drug-makers, and confused messaging from authorities about the safety of the AstraZeneca vaccine, which has been linked to rare blood clots.

The slow rollout, which Morrison says is due to ramp up in coming months when new supplies arrive, has been criticized by health experts and political rivals, with Labor leader Anthony Albanese saying it’s a result of the government inking deals with too few vaccine-makers, for too few doses.

Morrison’s predecessor as prime minister Malcolm Turnbull, who represented the same conservative Liberal Party, has weighed in. In an interview with the Australian Broadcasting Corp. on Thursday he described the rollout as “inexcusable.”

“I can’t think of a bigger black-and-white failure of public administration than this,” Turnbull said. “Governments make lots of mistakes of course, as we all do, but this is something that was very doable.”