Prime Minister Jacinda Ardern has accused Australia of "abdicating its responsibilities" by forcing New Zealand to deal with a detainee arrested at the Turkish border.
A 26-year-old mother identified as a terrorist belonging to Islamic State, along with her two children, have tried to enter Turkey illegally from Syria, according to the Turkish Ministry of National Defence.
The woman, named by the initials S.A., was identified as a Kiwi and was wanted through an Interpol blue notice - an international request for nations to share information regarding her identity, location, and activities in relation to a crime.
Ardern said on Tuesday the Government is in contact with Turkish authorities following the arrest of the woman, and revealed that she once had dual New Zealand-Australian citizenship, until the latter was revoked.
"The woman in this case has held New Zealand and Australian citizenships and has been known to Australian and New Zealand authorities for some time," Ardern told reporters.
"The fair question to ask is whether she should return to New Zealand or Australia. We firmly believe the answer is Australia - and have repeatedly communicated that view to the Australian Government at the highest levels."
Ardern said "unfortunately" the Australian Government unilaterally cancelled her citizenship.
"It is wrong that New Zealand should shoulder the responsibility for a situation involving a woman, who has not lived in New Zealand since she was six, has resided in Australia since that time, has her family in Australia and left for Syria from Australia on her Australian passport."
Ardern said any "fair-minded person" would consider the woman an Australian.
She said the Government believes Australia has "abdicated its responsibilities" by cancelling the woman's citizenship, and has shared her view with Australian Prime Minister Scott Morrison.
"Where dual citizenship is involved, our view has been that it's for New Zealand and Australia to resolve the most appropriate response and ensure that we do not strip citizenship and render someone stateless, especially when children are involved," Ardern said.
"We continue to urge Australia to cooperate in the management of these cases. The welfare of the children also needs to be at the forefront in this situation. These children were born in a conflict zone through no fault of their own."
Ardern said going to New Zealand, where they have no immediate family, would not be in the family's best interests and that Australia would be more suitable.
"We know that young children thrive best when surrounded by people who love them. We will be raising these points with the Australian Government," she said.
"We will be engaging with the Turkish authorities, and given there are children involved, their welfare will be top of mind in our response."
It's not the first time Ardern has lashed out at Australia for not taking responsibility.
Standing alongside Morrison in Sydney early last year, Ardern urged Australia to "not deport your people and your problems", referring to a policy of deporting Kiwis back to New Zealand, even when they have no connection to the country.
Morrison said he had no intention of changing the policy. He said it is "not directed to any one country or any one nationality whatsoever", and that Kiwis would not get any special treatment.