New coronavirus variants are forcing Australia and New Zealand to rethink already-stringent quarantine rules for overseas visitors, even as their systems are replicated around the world.

Officials in Australia's Victoria state became the latest to warn that the spread of the UK, Brazilian and South African mutations mean its 14-day mandatory quarantine must be toughened, according to AFP.

Health authorities in both Australia and New Zealand this week launched full reviews of quarantine facilities and procedures. Proposals range from developing outback quarantine centres to testing arrivals more often and for longer.

Since the beginning of the pandemic, around 320,000 travellers have been scooped up at Australian and New Zealand ports and airports, shuttled to quarantine hotels and confined to their rooms for 14 days.

But there is growing concern about the durability of the protocol.