The move effectively creates a Canberra bubble, banning regional NSW residents, outside of neighbouring regions, from entering without an exemption.

People who live across the border in communities including Queanbeyan, Yass, Murrumbateman and Collector will be able to enter Canberra to attend essential work or for other essential reasons such as groceries or healthcare.

The ACT has entered a seven-day snap lockdown with few essential reasons to leave home, following the announcement of a man who was infectious with COVID-19 while in the community.

Police will ramp-up border checks on NSW number plates at the ACT border.

ACT chief police officer Neil Gaughan said vehicles with NSW number plates would be stopped at the border.

READ MORE COVID-19 NEWS:

"People with NSW plates can expect to be pulled over and if they're not an exempt person or they don't have a reason for being in the territory they'll either be turned around, be fined or be arrested," he said.

ACT Health Minister Rachel Stephen-Smith said anyone from the exempted regions must carry identification in case they were stopped.

"Please make sure you are carrying identification because the decision we have made around the rest of NSW means ACT Policing will be very vigilant in looking out for NSW number plates," she said.

Residents of the exempted areas must be able to prove they live in that region and are travelling to the ACT for an essential purpose.

"To all of those in the local region, we know you're part of our community. We really need your help to abide by the same rules that Canberrans are abiding by and absolutely minimise your travel into the ACT," Ms Stephen-Smith said.

Anyone outside of the exempted areas must apply for and receive an approved exemption to be able to travel to Canberra.

NSW Deputy Premier John Barilaro said stay-at-home orders will apply to anyone in NSW who was in Canberra on or after August 5.

"Stop the spread and don't leave Canberra. I'll be asking Commissioner Fuller to ramp up police resources on the South Coast looking for blue and white number plates. Large penalties will apply," he tweeted.

Seven people were turned back after attempting to enter the ACT on Tuesday, a number ACT Policing said was "worrying".

"As the situation has continued to deteriorate we've continued to stop vehicles at the border," Deputy Commissioner Gaughan said.

"We've already made contact with our colleagues in Queanbeyan.

"We can expect people with NSW plates coming across the border to be stopped."

Our coverage of the health and safety aspects of this outbreak of COVID-19 in the ACT and the lockdown is free for anyone to access. However, we depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support. You can also sign up for our newsletters for regular updates.

MORE COVID-19 NEWS: