NSW has recorded 27 new locally acquired Covid-19 cases in the 24 hours to 8pm yesterday and its lockdown is being extended.
The source of nine of those cases remains under investigation.
Greater Sydney's lockdown has been extended for another week - until 12:01am on July 17.
The social distancing restrictions in regional areas have also been extended.
NSW Premier Gladys Berejiklian said the decision to extend lockdown was a difficult one.
"We appreciate and understand the stress this means for individuals, for families and, of course, for businesses. But what would be far worse is being in a situation where you have to live in and out of lockdown until that period of time when we have the vaccine available to us," she said.
"That is not a way to live and we want to give our citizens the best chance of staying safe and healthy."
Berejiklian foreshadowed an increase in the number of infections tomorrow because of higher case numbers in Fairfield, Canterbury-Bankstown and Liverpool areas.
"Can I say to the communities in those area, many have a similar background to me, please don't mingle with family. I haven't seen my parents since the lockdown started - it is hard," she said.
"Can I say to everybody don't mingle with family, don't think it is OK to visit your cousins or have sleep overs. Please, in those three local government areas limit your movement."
More than 45,000 people were tested overnight, an increase from 32,000 on Tuesday.
Meanwhile in Queensland, almost 10,000 contacts have been identified across five clusters of Covid-19, with the state recording just one new locally acquired case today.
The person was in home quarantine and lives in the same house as two others who had already been diagnosed at Tarragindi, in Brisbane's south.
"I think Queenslanders should be extremely happy with that news," Premier Annastacia Palaszczuk said.
Palaszczuk said she would need updated information from NSW before making decisions about border closures.
In the state of Victoria, it has been a week without detecting any new local cases.
Masks will no longer be mandatory in schools and private workplaces from Friday, as the state continues to gradually ease out of its recent lockdown.
Acting Chief Health Officer Deb Friedman said she was very pleased the state would be able to take the "cautious steps" to eased restrictions.
"These steps are taken recognising the incredible achievements that Victorians have made in overcoming the recent outbreaks," she said, "But we also recognise the significant risks that remain on our doorstep."