Prime Minister Scott Morrison announced the new measures on Friday for working holiday-makers, who will have to register quarantine with the government.

"This is being done to ensure those producers can get the work done but also to ensure that the communities are protected," he told reporters in Canberra on Friday.

Once the self-isolation period is completed, farmers and other employers will have to check backpackers' documents before they can start work.

Mr Morrison said it was important rural and regional areas without coronavirus did not face infections being brought in from cities.

Horticulture farmers have raised concerns about increased labour shortages to help harvest produce during the pandemic.

Mr Morrison also urged backpackers to follow social distancing rules after reports some continued to flout public health orders.

"You can't have six backpackers in a caravan, up out in rural parts of the country. That's not on. Not going to happen," the prime minister said.

He said state and local governments would be policing activities to make sure rules were followed.

Australian Associated Press