The Prime Minister has come out swinging at Australia over its decision to revoke the citizenship of a woman detained at the Turkish border, who reportedly attempted to enter from Syria.
It essentially means responsibility now only lays in the hands of New Zealand, despite Ardern previously asking Australia to work together over the woman's status.
Australian broadcaster ABC reports the woman is Suhayra Aden, who travelled to Syria "several years ago to live under Islamic State".
"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," Jacinda Ardern said.
"Australia has abdicated its responsibilities in relation to this person and I have personally made that point to Prime Minister (Scott) Morrison."
It comes after the Turkish Ministry of Defence tweeted that three New Zealand nationals tried to "enter our country illegally from Syria".
Vision released shows a woman and two children. It added they were caught by border guards and had terrorist links.
"Someone has identified themselves as a citizen of New Zealand accompanied by two small children has been detained at the Turkish border," Jacinda Ardern told media today.
"This is an individual known to Australian and New Zealand authorities for some time."
The person left New Zealand at the age of six. They were a resident in Australia "from that time, became an Australian citizen, left from Australia to Syria and travelled on an Australian passport".
Ardern said at this time New Zealand raised its concerns with Australia "around resolving if in the eventuality in their detention, or potential return, for whom the responsibility for those individuals should reside".
"Our very strong view on behalf of New Zealand and New Zealanders was that this individual was clearly most appropriately dealt with by Australia.
"That is where their family reside, that is where their links reside and that is where the place from which they departed for Syria."
Ardern raised it directly with Morrison and asked to work together.
She was then told the next year that Australia had unilaterally revoked the citizenship of the individual.
"You can imagine my response."
When asked about the situation today, Scott Morrison said it was his job as the Australian Prime Minister "to put Australia's national security interests first".
He said laws passed in Australia automatically cancel the citizenship of a dual citizen "when they’ve been engaged in terrorist activities of that nature".
"Australia’s interest here is that we do not want to see a terrorist who fought with terrorist organisations enjoying privileges of citizenship, which I think they forfeit the second they gauge as an enemy of our country."
Security expert Paul Buchanan said Australia was "openly shirking their responsibilities to their own citizens".
"The Australian behaviour is despicable on a couple of fronts, not the least of which is the diplomatic front with regards to us."
Ardern said they had "continually raised with Australia our view their decision was wrong".
"The welfare of the children also needs to be at the forefront in this situation. Coming to New Zealand, where they have no immediate family, would not be in their best interests.
"We will be engaging with the Turkish authorities, and given there are children involved, their welfare will be top of mind in our response."
When asked this morning if New Zealand should block the person's return, National leader Judith Collins said that "most New Zealanders like me, would consider such a person not someone we would go out of our way to assist back to New Zealand ... other than meeting the obligations the Government has to".