The UN is urging Australia to take responsibility for the 380 people who remain in the now closed Manus Island detention centre.
The situation for hundreds of asylum seekers stranded on a Papua New Guinea island is getting worse every day, a UN refugee official says, urging Australia to resume its responsibility for them.
Australia closed the offshore detention centre on Manus Island at the end of October, but some 380 refugees and asylum seekers have refused to leave, citing safety fears outside the centre's walls.
"The situation on the ground is very serious and deteriorating day by day," said Nai Jit Lam, a regional representative of the UN Refugee Agency (UNHCR) on Tuesday.
Lam said medicines ran out last week, their health is suffering in the hot and humid weather, and they have started digging wells inside the centre to get water.
The 250 others who have moved out of the centre face an apprehensive local population and unfinished alternative housing on the island, Lam said, adding that the migrants do not speak the local language.
"Australia must continue to take responsibility and play an active role in achieving solutions," Lam said.
The United Nations had long criticised the living conditions on Australia's offshore migrant centres, while the government argued that they deter people smugglers.
Last year, Papua New Guinea's Supreme Court ruled the Manus camp illegal and asked the government to close it.