Prime Minister Scott Morrison has warned that Australians are likely to have to change their way of life for six months as health authorities predicted there will be an exponential increase in coronavirus cases within the next few weeks.

“This will be a difficult six months. It could be longer. It could be sooner than that,” he told ABC radio on Monday.

Morrison’s timeframe came as Deputy Chief Medical Officer Paul Kelly warned Australia’s coronavirus death toll could reach up to 150,000.

Kelly said “somewhere in the range” of 20 to 60 per cent of the population could be infected.

“The more we can do to separate people and stop the disease spreading, the better. The death rate is around 1 per cent. You can do the maths,” he said.

Kelly urged people to practice social distancing to prevent a dramatic increase in cases in the coming months.

As of Monday, there were 368 COVID-19 cases reported in Australia, with the death toll remaining at five.