Asylum seekers will no longer receive taxpayer-funded immigration advice if they arrive in Australia through unofficial channels.
Immigration Minister Scott Morrison said that from Monday, asylum seekers who arrived without proper visas, either by boat or plane, won't be eligible for free help under the Immigration Advice and Application Assistance Scheme.
The cut will save the federal government $100 million over four years.
"There is also the issue that people who come to this country in that way won't be getting the taxpayer funded assistance that fills into the expectation," Mr Morrison told ABC radio.
Asylum seekers will continue to be given instructions setting out the asylum process and interpreters.
"They'll have the system explained to them."
Mr Morrison also said the withdrawal of the taxpayer-funded assistance wouldn't prevent asylum seekers from accessing legal advice and organisations were free to provide immigration advice and assistance for free if they wished.
A small amount of support will be offered to vulnerable people, such as unaccompanied minors.
"Whether someone is a refugee or not is determined by the process. And what we're saying is that it's not going to be the responsibility of the taxpayers anymore to fund people pursuing appeals and various other things through the process," Mr Morrison said.
"If people want to do that they can. If people in the community want to support people to do that they can, and we'll facilitate that. But it's not something we're going to put on the taxpayer as we said clearly before the last election. "
Saturday marked 100 days since the last asylum-seeker boat arrived in Australia.
Mr Morrison declined to say how many boats had attempted to make the voyage before being turned during that period.
"People will still try, they have tried and failed," he said.
"It's our job to make sure they continue to fail."
The minister will visit Port Moresby this week for talks with his Papua New Guinea counterpart on resettlement arrangements for asylum seekers on Manus Island.
PNG has said it will resettle some, but not all, of the asylum seekers and is urging other countries in the Pacific region to share the burden.
Asked what will happen if no other countries offered to take asylum seekers, Mr Morrison said: "They'll remain until they returnvoluntarily".