The NSW lockdown will not end until the number of cases in the community while infectious is closer to zero, NSW Premier Glady Berejiklian has warned.
There were 98 locally-acquired cases of COVID-19 in the 24 hours to 8pm on Sunday, with 20 of those in the community while infectious for more than one day.
It comes as increased surveillance testing has led to longer waiting times for results, with some people waiting up to three days.
Ms Berejiklian said two-thirds of the new cases were in south-western Sydney.
"Sometimes you don't even have to have symptoms to give the virus to loved ones," she said."Even when you don't have symptoms you might not know you're carrying the virus. This variant of the virus makes you more transmissible."
Ms Berejiklian said transmissions had also been occurring in workplaces.
"That's why we have had to ask some businesses to down tools," she said. "We won't see the effect of the harsher restrictions until the next couple of days.
"I know NSW is up to the task. I know we can beat this thing.
NSW chief health officer Dr Kerry Chant said of the 98 locally-acquired cases, 20 were infectious while in the community for over one day.
"It is important we get that number down," she said "COVID is a severe illness."
There are now 80 people in NSW hospitals with COVID-19. Of those, 24 are in intensive care. One had been vaccinated with one dose of AstraZeneca.
Victoria will stay in lockdown beyond the original five days after recording 12 more cases and exposure sites appearing across the state.
There were 13 new local infections in the 24 hours to Monday morning, one of which is a case in Mildura, previously announced by authorities.
Premier Daniel Andrews on Tuesday said there were too many chains of transmission for the lockdown to lift at the original time of midnight Tuesday.
"We are running alongside this virus, but we're not yet in front of it," he told reporters.
"We've gone hard and early and I think we have avoided, in fact I know we have avoided something altogether worse."
- with AAP