Prime Minister Scott Morrison says there will be a review into JobKeeper at the end of June.

"I need to stress again that was a temporary lifeline put in place to help Australians through the worst of this crisis. It comes at a very significant cost," he told reporters in Canberra on Friday.

States and territories have begun the process of gradually easing restrictions, with the aim of implementing all three stages of the plan by July.

By then, cafes, restaurants, shops, gyms, beauty therapists, cinemas, theatres, amusement parks, galleries and museums would be re-open.

The $1500 fortnightly JobKeeper payments started flowing to employers on Wednesday.

They're legislated until the end of September.

While the program was budgeted to cover six million employees, it has had a lower than expected take up.

About 768,000 businesses have enrolled for the program, with about 40 per cent of those sole traders.

But Mr Morrison has ruled out further extending the program to include casuals and migrant workers.

"JobKeeper is a demand-driven program. It doesn't have a target level of subscriptions at all. Never has," he said.

"Estimates were made at a time when things were very uncertain about where things are heading. The fact that fewer may ultimately seek or need that support is a good thing."

Australian Associated Press