Speaking at an online address to major businesses on Friday, Mr Frydenberg said markets would bounce back strongly next year after Delta variant outbreaks.

"We will start to see a strong comeback for household consumption," Mr Frydenberg said.

"We're expecting consumption and investment to pick up once we're out of lockdown in the two major states of NSW and Victoria."

The treasurer's comments come following the assessment earlier this week by the OECD that the Australian economy would expand by four per cent in 2021.

However, that figure was a drop of 1.1 per cent from the organisation's earlier forecast in May.

Mr Frydenberg said the Reserve Bank of Australia had also forecast similar growth levels for the country in the months ahead.

"Delta has been a big hit to the economy, and not just in economic activity, but the fiscal cost that has been running to support households," he said.

"It's important to stick to the national plan agreed to at national cabinet and open in accordance with the plan, because we expect to see the economy bounce back."

While jobs figures released last week showed unemployment had fallen to some of their lowest levels in more than a decade, new data has pointed to further big employment losses on the horizon.

August unemployment figures from the Australian Bureau of Statistics showed a drop from 4.6 to 4.5 per cent.

However, the heads of some of Australia's biggest banks told a federal inquiry that the unemployment rate was expected to reach more than five per cent by the end of the year.

Mr Frydenberg said there had been strong signs of economic recovery in Australia.

"There has been a lot of resilience across the economy," Mr Frydenberg said.

Australian Associated Press