MELBOURNE (REUTERS) - Australian Treasurer Josh Frydenberg said on Sunday (May 16) that the government will stick to plans to start reopening the country only from the middle of next year, as pressure mounts on the ruling conservatives to end the international border closure.

"We will follow the medical advice that has served us very well through this crisis," Mr Frydenberg said in a television interview with the Australian Broadcasting Corp.

Australia closed its borders to non-nationals and non-residents in March 2020 and has allowed only limited international arrivals in recent months, mainly citizens returning from abroad.

The closure, combined with snap lockdowns, swift contact tracing and public health compliance have made Australia's Covid-19 pandemic control measures among the world's most effective.

Cases of coronavirus infection total around 29,700, with 910 deaths.

The government's reopening plans, unveiled this week, have sparked criticism from businesses and industries, as well as politicians within Prime Minister Scott Morrison's Liberal Party.

"Like many measures, international border closures had a temporary place, but it is not sustainable and will turn us into a hermit outpost," Mr Tim Wilson, a Liberal Party Member of Parliament from Melbourne, was quoted as saying by The Sunday Age.

The newspaper also published recordings from Victoria's Chief Health Officer Brett Sutton, one of the architects of Melbourne's 111-day strict and successful lockdown last year, who suggested that Australia must start thinking about a reopening strategy once there is high vaccination coverage.

In its budget unveiled last week, the government envisaged that all willing Australians will be vaccinated by the end of the year.

While hurting many businesses that depend on international travel and workers, the border closure gave the country's first travel surplus in years, as Australians - avid travellers - traded international forays for local excursions.