The United Nations High Commission for Refugees has sent a delegation to Papua New Guinea to monitor events at Australia's immigration detention centre on Manus Island.
The UNHCR said it was monitoring is the departure of refugees for resettlement in the United States and the ongoing closure of the centre.
The agency said Australia's plan to abruptly withdraw services and support for detainees at the end of October remained highly concerning.
It said it wouldcontinue to advocate for the detained men with the governments of PNG and Australia, the latter being a signatory to the UN Refugee Convention.
The UNHCR said Australia remained responsible for those it detained for seeking asylum.
The statement from UNHCR:
"A UNHCR delegation is present in Papua New Guinea this week monitoring the departure of the first refugees to the United States, as well as the ongoing closure of the Manus Island "Regional Processing Centre". In this context, Australia's abrupt planned withdrawal of services and support remains highly concerning, and UNHCR is continuing to advocate with both governments involved. As a signatory to the 1951 Refugee Convention, Australia remains responsible for those who sought its protection."