Following a triple-digit rise in daily Covid-19 cases on Monday for the first time in over a year in New South Wales (NSW), the Australian state's Premier Gladys Berejiklian said the scheduled lifting of the lockdown in Sydney this week is "almost impossible".

"Where the numbers are, it is not likely, in fact, almost impossible, for us to get out of lockdown on Friday," Xinhua news agency quoted Berejiklian as saying to reporters here.

The state recorded 112 new locally acquired cases on Monday, which increased the the total number of infection in the latest outbreak to 678.

It is the first time that more than 100 cases have occurred in a single day in NSW since April last year.

Among the new local cases, the source of infection for 48 cases remains under investigation, while 34 were transmitted in the community.

The NSW government announced it would further ramp up its vaccination drive, with the AstraZeneca jab to be made available to all people aged over 40 at NSW mass vaccination clinics.

Teachers and aged care workers in the Fairfield, Canterbury Bankstown and Liverpool local government areas where there is greater concern of Covid-19 transmission will be prioritised.

NSW has also approached the federal government to ask that any unused Pfizer vaccines be redirected to NSW health hubs.

These changes will be complemented with the opening of three new mass vaccination centres and a large vaccination clinic in the coming weeks, adding to the 100 NSW Health vaccination clinics and outreach locations across the state.

At the same time, customers and businesses are reminded that from Monday the use of the NSW government's Covid-Safe Check-In will be mandatory at most workplaces and retail businesses in the state.

Minister for Digital and Customer Service Victor Dominello said check-in information from these additional venues is critical to supporting the work of NSW Health contact tracing teams in the fight against the highly contagious Delta variant.