Cars are crossing the NSW border into Victoria without being checked, according to a local mayor, after a state government request for additional Defence support received a limited response.
The Victorian government requested 200-300 Australian Defence Force personnel to help with planning, logistics and surveillance on Saturday night.
Defence has so far only committed to 50 additional personnel.
"We are not pleased ... we are not happy that it seems that request has been turned down," Victorian Premier Daniel Andrews told reporters on Monday.
"What that simply means is more members of Victoria Police and more SES volunteers will have to be on that border right throughout Christmas."
Victoria on Sunday announced it was shutting its border to people travelling from greater Sydney and the NSW Central Coast over a growing coronavirus cluster.
Health Minister Martin Foley on Monday said 700 police had been deployed to patrol the NSW border.
He said local government area bubbles had been established on either side of the Victorian-NSW boundary to allow those in border communities to cross upon presentation of their driver's licence.
However, Wodonga mayor Kevin Poulton said he crossed from his Albury home to Victoria in the regular 15 minutes without being stopped or checked by police.
"They're still putting their measures in place at the moment ... nothing was checked," Mr Poulton told 3AW Radio on Monday.
"It looks like they're working extremely hard to get themselves ready. They're setting up a fairly significant operation here."
Police Association Victoria secretary Wayne Gatt said extra help from the ADF was crucial given policing was at its "busiest" in December.
"Without the support of those men and women we'd be on our knees by now in terms of resourcing," Mr Gatt told 3AW Radio.
Defence say they already have 235 personnel supporting Victoria's hotel quarantine program and any additional ADF backup will "not provide direct support to vehicle checkpoints on the NSW/Victoria border".
A defence official earlier told AAP more than 3000 ADF personnel had been deployed to Victoria since June.
They said another 50 personnel would be set to provide planning and logistics support after requests for additional support.
From Monday, most people travelling from greater Sydney and the NSW Central Coast - or who visited those areas since December 11 - will not be able to enter Victoria.
Anyone who is permitted to enter will have to undergo 14 days of hotel quarantine.
The one exception is returning Victorians, who have until midnight on Monday to return if they want to be allowed to quarantine at home.
Mr Andrews said the border to NSW would remain closed for as long as Victorian chief health officer Brett Sutton believes is "proportionate and appropriate".
He said anyone arriving at Melbourne Airport from Sydney who had just completed 14 days of hotel quarantine in NSW would not be required to repeat the process in Victoria, so long as they travel directly from hotel to airport while wearing a mask.
"There might be some testing and a short time you have to stay home, but we are not envisaging people having to do another two weeks of hotel quarantine if you're coming out of hotel quarantine," Mr Andrews said.
People from greater Sydney flying to Victoria were on Sunday allowed to pass into Melbourne Airport without testing on the spot but were encouraged to get tested and self-isolate until receiving their results.
Some travellers from Sydney were also able to walk through the airport without wearing a mask.
The NSW government announced 15 new locally transmitted cases on Monday, all of which were linked to an outbreak on the city's northern beaches that now totals 83 cases.
Victoria has reported no new local coronavirus cases for the 52nd day in a row.
One new case acquired overseas was found in hotel quarantine after 13,695 test results were received in the past 24 hours.
Australian Associated Press