New South Wales has recorded 78 new COVID-19 cases and one new death as neighboring state South Australia enters lockdown as its cases rise to five.
In addition, Victoria's lockdown has been extended for another week.
The latest death from the virus was a woman in her 50s, who was a close contact of a COVID-19 case.
NSW Chief Health Officer Kerry Chant urged people to act as though they are infectious to try and stop the spread of the virus.
"We need to consider whenever we leave our house, anyone we come into contact with could carry the virus - while its human nature to be friendly, unfortunately, this is not the time to do this."
Unfortunately, the virus has spread to South Australia, with an 81-year-old man and two close contacts testing positive on Tuesday.
Premier Steven Marshall announced the state will enter lockdown at 6pm on Tuesday.
It's feared the 81-year-old was infectious in the community for as long as five days.
"We’ve only got one chance to get this right," Marshall is quoted as saying by 7 News.
"We are very concerned. We are treating this as the Delta variant. We are going to go hard and go early."
Premier Gladys Berejiklian said on Tuesday while it's "pleasing" to see a drop in the NSW numbers - it's not all good news.
"We still had 26 people infectious in the community so that's the number we want to see going down."
The new cases come after 63,000 people got tested for the virus.
Berejiklian stressed it was important to get tested - even if people are not showing symptoms.
"If you're in a community with a lot of cases, even if you don't have symptoms don't assume you don't have the virus. You can have it and not know it."
It comes as neighboring state Victoria, recorded 13 new cases on Tuesday and extended its lockdown a further seven days.
Premier Daniel Andrews said more time is needed to contain the state's outbreak.
"We are all going to work very, very hard to have Victoria begin the process of opening up at midnight next Tuesday, 27."
"We wish we could bring this in earlier, but we can’t run the risk that there are cases out there that we don’t know about. There are chains of transmission that are not yet contained that we don’t know about."
One case was also recorded in Queensland - unrelated to any of the state's current clusters.
Health Minister Steven Miles said the infection was detected in a woman, aged in her 20s, who travelled from Victoria last week.
The woman travelled from Melbourne to Maroochydore on July 13, and was told two days later she had been in a location of interest.
She got tested and returned a negative, so went out and about the Sunshine Coast and Cairns before developing symptoms.
She is fully vaccinated with the Pfizer vaccine - something health experts say reduces but doesn't remove risk.