Scott Morrison has backed heavy restrictions to suppress coronavirus after cases surged in Sydney and Melbourne's lockdown was extended.
NSW reported 344 new local cases after a record 356 the previous day, while six people in the past 48 hours have died.
There were 20 new local cases in Melbourne for a second consecutive day, prompting at least a one-week lockdown extension.
NSW Premier Gladys Berejiklian again hinted at a slight easing of restrictions if her state hit a 50 per cent vaccination target by the end of the month.
But the prime minister insists aggressively driving cases down until higher immunisation rates are reached is paramount.
"It's important we continue to suppress the virus in the first phase because we want to make sure every member of your family is around that Christmas table at the end of this year," he told parliament.
"Suppressing that virus now is incredibly important."
Australia's leaders have backed 70 per cent full vaccination coverage to significantly reduce the chances of lockdowns.
A target of 80 per cent has been set for a wider relaxation of travel rules and all but ending city-wide shutdowns.
Ms Berejiklian expects her state to reach 70 per cent full vaccination by the end of October and 80 per cent around mid-November.
Dubbo has joined other regional areas of NSW in lockdown with smatterings of the virus escaping Sydney.
Victorian Premier Daniel Andrews pulled the trigger on another week of Melbourne's sixth lockdown after five of the 20 new infections were mystery cases.
Australia has fully vaccinated 23.7 per cent of people aged 16 and over with a record 255,964 doses administered in the past 24 hours.
Labor's health spokesman Mark Butler said the prime minister shared responsibility for Sydney's outbreak which has now claimed 34 lives.
"These tragedies reinforce just how wrong Scott Morrison was when he said that this was not a race," he said.
Some experts have predicted Australia could get to 70 per cent fully vaccinated in mid-November but vaccine rollout commander John Frewen is reluctant to set a date.
"As long as Australians keep turning up I think we've got a really fantastic opportunity at getting to 70 per cent before the end of the year," he told 3AW radio.
"If everything went right and everyone turned up in droves, we've got another opportunity for 80 per cent this year."
Infectious disease expert Peter Collignon believes the prime minister's Christmas target to reunite families is realistic.
"You may not have 100 people around your table but you could have a fair few for two reasons," he told the Seven Network.
"We're getting more and more vaccines out - we've got about 14 million out, we're doing about one million a week - and also then winter and early spring is over so viruses also transmit less."
A three-day lockdown in Cairns ended on Wednesday afternoon after no new cases were detected.
There were four new local cases linked to the Brisbane outbreak with all in isolation during their infectious period.
Australian Associated Press