Australia should restore food, water and health services to 600 men inside the Manus Island immigration processing centre and end the “unfolding humanitarian emergency”, the UN human rights office says.

Hundreds of men remain in the centre on the Papua New Guinea island that officially closed on Tuesday, saying they do not feel safe in the replacement accommodation at Lorengau.

UN High Commissioner for Human Rights spokesman Rupert Colville said it shared wider UN concerns about the stand off.

“We have serious concerns about the welfare, safety and wellbeing of the roughly 600 men who remain in the accommodation compound, who are too frightened to leave,” he said.

Inside the Manus detention centre

Refugees are stockpiling water and say they can survive for a month without food.

“We call on the Australian Government, as the party who interned the men in the first place, to immediately provide protection, food, water and other basic services.

“The men have said they fear they will be subjected to violence at the hands of locals if they leave the compound — and, given there have been violent incidents in the past, we believe these fears should be respected and satisfactorily addressed.”

Mr Colville said both Australia and PNG were responsible under international human rights law and the 1951 Refugee Convention, to protect the men from harm and ensure they had access to shelter, water, food and sanitation.

He repeated previous UN concerns about Australia’s offshore processing centres, saying they “are unsustainable, inhumane and contrary to its human rights obligations”.

“We urge the Australia Government to transfer the men to mainland Australia where their claims can be processed,” Mr Colville said.

Immigration Minister Peter Dutton’s office declined to comment on the statement but earlier this week flagged there would be no change in Government policy to allow the men entry to mainland Australia.

“The Illegal Maritime Arrivals [IMAs] who are refusing to leave the RPC have been aware since May this year that the PNG authorities would close the RPC [regional processing centre],” he said.

“The constant claims of IMAs and advocates about their situation in Manus are nothing more than subterfuge.

“They have long claimed the Manus RPC was a ‘hellhole’ but the moment it was to be closed they demanded it be kept open.”

New Zealand’s offer still on the table

On Friday, New Zealand’s new Prime Minister, Jacinda Ardern, renewed her predecessor John Key’s offer to resettle 150 asylum seekers currently in Australia’s offshore detention centres.

Opposition Leader Bill Shorten said Prime Minister Malcolm Turnbull should seriously consider New Zealand’s offer.

“Australia is not and must not be a resettlement option but it is [Prime Minister Malcolm] Turnbull’s responsibility to work with other nations on resettlement options,” Mr Shorten told the ABC.

“There are strong similarities between this plan and the deal with the United States.”