The Papua New Guinea Supreme Court has forced the closure of Australia's offshore detention centre for asylum seekers, but about 400 of them are refusing to move to new accommodation in the community despite power, water and food having been cut off.
Ardern is starting to gain some attention in Australia with Government minister Matt Canavan calling her comment a "PR stunt."
She said it was a genuine offer by New Zealand as it was when it had first been made by another Government and another leader, John Key to Julia Gillard in 2013.
She rejected a suggestion that she could be seen as interfering in Australia's domestic affairs.
"Not if I am working closely with them."
Ardern began a series of bilateral meetings yesterday - with Canada's Justin Trudeau, China's Li Keqiang, and Indonesia's Joko Widodo.
She invited Trudeau to visit New Zealand and Antarctic, perhaps before the 2018 Apec summit in Papua New Guinea.
However she told reporters she was none the wiser as to why Canada had skipped the final TPP leaders meeting in Vietnam without notice, causing it to be abandoned.
Commenting on the Green Party's decision to oppose the revised TPP - now renamed the Comprehensive and Progressive Agreement for Trans Pacific Partnership - she said she had expected that after discussing it with Greens leader James Shaw before leaving New Zealand.
"I knew that would likely be their position...We discussed it. We were fully informed. This will from time to time be an outcome of a Government that does bring together multiple parties.
"From time to time we will take different positions."
National has already pledged to support the required legislation to get the revised deal through but Ardern is not yet sure what New Zealand First's position will be.
She is not expecting to know that until the agreement is finalised.
She says New Zealand First is able to agree to disagree despite being inside the cabinet.
"I absolutely understand that as a political party they will want to see the final deal on the table. There's a little bit of work yet to be done."