A total of 439 people remain in Australian detention centres on Nauru and Papua New Guinea's Manus island, nearly 20 months after first being intercepted.
Tania Cutting from Australia's Department of Immigration and Indigenous Affairs, or DIMIA, says 51 of those are refugees for whom they are still trying to find resettlement countries.
She says 258 of the remaining group have refused to accept the repatriation package which was offered to them.
But, Ms Cutting says they will be returning home at some point.
"Essentially what it means is those people who did not accept the package will at some stage have to return home. There is no discussion at this stage of forcible returns. The focus at the moment is on the resettlement of the 51 refugees and on repatriating those who have accepted the package."
Australia shipped nearly 1200 people to its detention centres in Nauru and Manus after they were intercepted on two boats bound for Australia.
Australia has since accepted 329 refugees from the 699 who have been resettled.