NSW premier Gladys Berejiklian admits border closure will be 'extremely difficult'

The New South Wales premier has defended claims of miscommunication and a lack of planning as the border along Victoria closes from today.

Restrictions are now in force for Greater Melbourne residents who are now unable to enter New South Wales.

And from tonight, all Victorians will only be able to enter NSW for very limited reasons, such as obtaining medical care or fulfilling a legal obligation.

Speaking to Today, Gladys Berejiklian said news of the closure needed to remain under wraps until it was confirmed.

It follows criticisms by mayors of the mayors of the border cities who say the sudden border closure has sparked disruption and uncertainty in their communities.

"We can't make those plans public until you make the decision," Ms Berejiklian said on Tuesday.

"We always knew that once we made the decision and we announced the decision, there would be two or three days where it would be extremely difficult for our border communities."

READ MORE: Everything you need to know about the Victoria-New South Wales coronavirus border closure 

NSW has not recorded any new cases of community transmission overnight, she said.

It comes as two cases of possible coronavirus within the border towns remain under investigation.

Ms Berejiklian admitted it wasn't possible how long the borders would be closed.

Those who need to move into either state still have time to do so before the hard lockdown comes into force from midnight tonight.

"We appreciate there are people who might live on either side who want to get back home and base themselves in their home state," Ms Berejiklian said.

"That's why whenever you make the announcement, you do need to give some time for people to make those adjustments because we don't know how long the border's going to be closed for."

Today will be the last day residents will be able to decide where to base themselves before the closure takes effect.

"Service NSW hopefully by today will have that permit system up and running so people can actually apply to get across the border for work purposes or for other essential services.

"We are working really quickly."