The detainees in the Manus Island Centre have defied attempts by Australia and Papua New Guinea to close the camp, saying they fear violent reprisals from the local community if they are moved to other "transit centres".
UN rights spokesman Rupert Colville decried the "unfolding humanitarian emergency" at Manus Island and urged Canberra to transfer the men to the mainland to assess their asylum claims.
"We repeat our overall concerns about Australian offshore processing centres which are unsustainable, inhumane and contradictory to its human rights obligations," Colville told a Geneva news briefing.