Tony Abbott has denied his office had any knowledge of the cancelled Australian Border Force operation in Melbourne on Friday, and said people in Australia would never be stopped by immigration officials in the street checking for visa details.

The Prime Minister said an Australian Border Force press release that said officers would be "speaking with any individual we cross paths with" was a clumsy mistake, and did not represent government policy.

"Obviously it was a mistake," Mr Abbott said in western Sydney on Saturday.

"It was over the top and wrong because we would never stop people randomly in the street demanding their visa details, we don't do that sort of thing in Australia and it would never happen under this government," he said.

Protests flared in Melbourne on Friday after Immigration and Border Protection issued a release saying ABF officers would join police and transport officials in an enforcement campaign known as "Operation Fortitude".

The initial release quoted ABF regional commander for Victoria and Tasmania, Don Smith, as saying that officers would be posted throughout central Melbourne speaking with any individuals they crossed paths with. Operation Fortitude was later cancelled, as was a press conference scheduled for Friday afternoon to answer questions about the operation.

Mr Abbott said he "wouldn't know" who the highest figure in the Department of Immigration and Border Protection was who cleared the press release.

"What was happening as part of this Victorian police operation to, I gather, crack down on anti-social and unlawful activity at transport hubs, was that anyone who the Victorian police suspected might have a visa issue would then be referred to Australian Border Force in the normal way," the Prime Minister told reporters in western Sydney, where he announced $4.5 million to help restore the woodland of the Cumberland Plain.

"Unfortunately the press release was very, very badly worded but no one had been, no one ever will be, randomly stopped in the street for some kind of visa check," he said.

But Mr Abbott said he would not be seeking answers from Mr Smith, and also seemed to absolve Immigration Minister Peter Dutton of responsibility.

"It was an operational press release," he said.

They go out under the authority of the relevant officials, they go out under the authority of the relevant agencies, and that all happens at arms-length from ministers, it all happens at arms-length from the executive."

Asked if he or his office was aware of the nature of the operation and of ABF's involvement, Mr Abbott shook his head.

"Nothing happened here except the issue of a poorly worded press release," he said later.