SOUTH Australia is enforcing stricter border controls to essential travellers from Victoria from Wednesday next week.

SA Police Commissioner Grant Stevens said an online portal would be set up for essential travellers to apply for approval by a centralised decision-making service before driving to a border location rather than the current self-assessment to help "weed out" people trying to undermine the principles of the SA COVID-19 lockdown.

"People who are deemed to not be essential travellers will have to do 14 days of quarantine coming into South Australia," Mr Stevens said.

"The general principles of our border restrictions have not changed -- essential travellers can move into the state and undertake the purpose of their visits and in some respects that will require them to quarantine when not undertaking those activities.

"People who are not essential travellers will be required to quarantine 14 days at a specific location."

There will be no significant assessments on freight transport operators.

SA Premier Steven Marshall said additional SA Police resources had been sent to locations along the South Australia-Victoria border.

"This (pre-approval) is something the police will be supervising and they will have members of SA Health within the office that is doing the authorisation," he said.

"The guts of the issue with regards to this is it helps business because it provides greater clarity and certainly it allows a greater level of scrutiny prior to that movement.

"We are looking at what is happening with Victoria extraordinarily carefully, but we as a nation have got on top of outbreaks and clusters before and I'm sure that is what will happen in Victoria."