By Sunday afternoon, about 600 refugees and asylum seekers remained at the Manus Island site, which closed on October 31 following a PNG Supreme Court decision.
The United Nations warned of an "unfolding humanitarian emergency" at an Australian detention centre in Papua New Guinea on Thursday, calling on Canberra to defuse a tense days-long stand-off between refugees and authorities.
But some 600 men have locked themselves inside - despite water and electricity being cut and dwindling food supplies - saying they are fearful for their safety if they move to transition centres amid reports locals do not want them there.
Nai said unease between the refugees and local communities had grown due to a lack of consultation when the transition centres were being constructed.
Australia has an obligation to do so under worldwide human rights law and the 1951 UN Refugee Convention, he said.
Under its tough immigration policy, Canberra sends asylum seekers who try to reach Australia by boat to two camps, in Manus and Nauru, and they are barred from resettling in Australia.
He further clarified that when he took office in 2002, there was already an arrangement in place on Manus Island for boat people who had fled their homeland destined for Australia.
Australia has brokered a deal with the USA, which will resettle 1250 refugees, subject to the Trump administration's "extreme vetting".
"But also we have urged Australia and PNG to de-escalate the situation, resume basic services - water, electricity, medical services as well".
Recorded messages from detainees on Manus Island have been played to a rally of hundreds of supporters in Melbourne's CBD.
"As the prime minister at the time I honoured the arrangement of the previous government but once the processing was completed, my government put a stop to this so-called Pacific Solution", Sir Michael said in his statement, adding any resettlement needs support services. "They force us to starve".
Ms Ardern revealed she did suggest to Mr Turnbull to take up both offers from New Zealand and the USA, but she said Mr Turnbull wanted to make sure the deal with the USA "actually comes to fruition".
Australia's Immigration Minister Peter Dutton insisted the new facilities were "much better" than being at the camp and said he wanted "to close Manus as quickly as possible".
"I acknowledge that, while New Zealand has not had to contend with these issues on our shores, it's hard to ignore the human face of this situation and nor should it be ignored", Ardern wrote.
Despite this, Australia have placed priority on an agreement with the United States to settle 1250 refugees. "You can't keep political hostages".
"We [PNG] can't all be blamed for resettling them here".
'New Zealand holds an obligation generally to make sure that we maintain our obligations to the United Nations to take refugees, ' she told reporters on Sunday morning.