Australia has suffered its deadliest day of the pandemic as a fast-moving Omicron outbreak continued to push up hospitalisation rates to record levels, even as daily infections eased slightly.

A total of 74 deaths were registered by late morning between New South Wales, Victoria and Queensland, Australia's three most populous states, exceeding the previous national high of 57 last Thursday, official data showed.

“Today is a very difficult day for our state,” New South Wales Premier Dominic Perrottet said during a media briefing, Reuters reported.

Just over 67,000 new infections were reported in New South Wales, Victoria, Queensland and Tasmania, down from a national high of 150,000 last Thursday. Other states are due to report later.