A human rights lawyer says Australia is scrambling to find places to move Manus Island detainees as its Papua New Guinea detention centre is closed.
The facility is due to shut completely at the end of the month, and on Tuesday detainees were offered relocation to Australia's other offshore immigration detention centre on Nauru.
Three buildings on Manus Island have been earmarked to receive about 600 men, while about 150 others are in a motel and houses in Port Moresby.
Only 25 out of about 900 Manus detainees have so far been resettled in the United States and the Australian government is currently building another prison camp in the PNG capital.
Lawyer Daniel Webb said the government's Nauru offer showed it was desperate.
"I mean this announcement comes three weeks before the slated closure of the Manus detention centre. And it comes in the wake of a recent spate of violent attacks against refugees in the community on Manus, and after two recent deaths. So the Australian governmnet is scrambling and it's not good enough."
Mr Webb said all detainees on Manus Island and Nauru should be brought to safety in Australia.