Victorian Premier Daniel Andrews has called for NSW to implement a ring of steel around Sydney.
It comes as NSW Premier Gladys Berejiklian declared a national emergency.
He said the whole country risks having to be locked down if the NSW situation is not handled properly.
"I want to make this point though, if there is a national emergency in Sydney, and I'm not doubting that for a moment, there is national responsibility that Sydneysiders are locked into Sydney," he said.
"We need a ring of steel around Sydney so that this virus is not spreading into other parts of our nation."
"Let's focus on what's going on in Sydney, let's focus on not spreading what's going on in Sydney across the rest of our country.
"We will finish up with the whole country locked down if we don't do this properly."
Mr Andrews said NSW had a very significant challenge, with many cases and many people in the community while infectious.
"That trend is not what you want to see," he said.
Mr Andrews said a total of 147 cases had been recorded in Victoria the last 11 days.
Seven people are in hospital, one of them is from hotel quarantine.
It comes as Victoria recorded 14 locally-acquired cases of COVID-19. Of the 14 new cases 10 were isolating for their entire infectious period. Three were in the community for a day. One is still being investigated.
Mr Andrews said the low number of infectious cases in the community was a triumph of the public health team and those in isolation.
There were 14,302 vaccines administered yesterday.
Mr Andrews said it was very difficult to predict where the state would be come the end of lockdown.
"I would say the trend is with us, the results are positive," he said.
Mr Andrews said the decision would not be made until they had all the information next week but reiterated the trend was positive.
Watch Mr Andrews speak below:
Yesterday, acting Chief Health Officer Ben Cowie said it was too early to say whether Victoria's lockdown would end as planned, but he was confident authorities have a handle on the outbreak.