SYDNEY • Australia will cut international arrivals by 50 per cent in a bid to halt a surge in the Delta variant of the coronavirus which this week forced half the population into lockdown, as the government starts looking at creating a road map out of the pandemic.

While the reduction of commercial flight arrivals will take the pressure off the hotel quarantine system, "that alone does not provide any fail-safe regarding any potential breaches" of the virus into the community, Prime Minister Scott Morrison told reporters in Canberra yesterday.

He said Australia will now accept only about 3,000 travellers from overseas a week. The cuts are expected to last until at least the end of the year.

Mr Morrison said state and territory leaders had also agreed to map out a pathway to switch from virus suppression to focusing on reducing the risk of serious illness and hospitalisation, depending on high vaccination rates that are yet to be determined.

In the meantime, the arrival cuts mean that even as other developed economies like the United States and Britain open up, Australia is further isolating itself after imposing strict border restrictions when the pandemic began 15 months ago.

A tardy vaccination rate - the second-slowest among the 38 nations in the Organisation for Economic Cooperation and Development - has made Australia particularly vulnerable to the Delta variant, which is increasingly leaking out of the 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 is allowing for too many non-Australian residents to enter the nation, sometimes with infections.

These infections have contributed to the lockdowns imposed in the past week in cities including Sydney, Brisbane and Perth. The outbreaks are also linked to mining workers and airline crew who have travelled around the nation.

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 Britain and the US, which have had relatively strong vaccination rates, a slow roll-out in Australia means the economy, and particularly domestic tourism, remains vulnerable.

Mr Morrison said Australia would start to treat Covid-19 differently as vaccination rates increase - similar to a move by Singapore.

The nation would incrementally implement a four-stage plan: 1) vaccinate and suppress the virus; 2) minimise serious illness, hospitalisation and death; 3) treat Covid-19 like other infectious diseases such as the flu; and 4) return to normal life, including lifting travel caps for vaccinated people and allowing a more porous international border.

"When it is like the flu, we should treat it like the flu, and that means no lockdowns," Mr Morrison said. Still, he gave no timelines or vaccination thresholds for the stages to be reached.

While 83.9 per cent of international arrivals last month were returning Australians, there are still 34,000 people trying to get home, Mr Morrison said.

Ms Gladys Berejiklian, premier of New South Wales state, said in Sydney: "My heart goes out to thousands of Australians who have to wait longer to come home."

She 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 yesterday from the day before.

"Just because you reduce the number of people coming in doesn't mean outbreaks aren't going to happen," she said.

BLOOMBERG, REUTERS