The United Nations High Commissioner for Human Rights is concerned Australia's re-opening of offshore detention centres could result in violations of human rights, including potentially indefinite detention.
Australia's Senate passed recently legislation to pursue offshore processing on Nauru and Papua New Guinea's Manus Island.
Navi Pillay has welcomed recent efforts in Australia to institute more comprehensive regional cooperation on migration.
But she is concerned that some aspects of the proposed changes could place at risk the human rights of migrants and asylum seekers.
The High Commissioner has reiterated her call for a rethink of Australia's asylum and migration policy.
She also urges political leaders to take a principled and courageous stand on migration and to break an ingrained political habit of demonising migrants and asylum-seekers.
Navi Pillay says she understands the proposed amendments to migration legislation followed recommendations from a panel of experts.