Immigration Minister Peter Dutton has told refugee advocates to stop giving what they think is honourable advice to asylum seekers on Nauru.
"While some may be encouraged by messages of false hope and some may resort to extreme action, this government will not be dissuaded from its stated border protection policies," he told reporters in Canberra on Tuesday.
Mr Dutton was responding to the latest self-harm incident on the remote Pacific island, in which a 21-year-old Somali woman set herself alight.
"I repeat the call to advocates today that their intentions may be honourable and they may be noble in their own minds but they are causing serious harm," he said.
The government was not going to change its policy of refusing to resettle anyone transferred to offshore processing centres on Nauru and Manus Island in Papua New Guinea.
"We are going to make sure that the advocates hear that message very clearly."
Mr Dutton said it was perfectly reasonable for advocates to offer refugees support.
"But to provide advice otherwise is very dangerous. We are seeing that play out at the moment. We are not going to allow for it to continue," he said.
Earlier, the United Nations refugee agency said offshore processing and prolonged detention was immensely harmful.
"Despite efforts by the governments of Papua New Guinea and Nauru, arrangements in both countries have proved completely untenable," the UNHCR said in a statement.