The deputy prime minister of New Zealand has demanded Australia take the Christchurch terrorist back after the gunman was handed a life sentence without parole.
Winston Peters said Australian-born Brenton Tarrant should be returned to the country that raised him.
"Now is the time for Australia's Minister of Home Affairs, Peter Dutton, to receive and carry out the terrorist's sentence in Australia," Mr Peters said on Thursday.
"The Islamic community and all of New Zealand has already suffered enough without having to pay astronomical prison costs to keep him safe in our prison system."
Prime Minister Scott Morrison has not received a request for the gunman to serve his time in Australia.
"It's normal practice that criminals convicted of these offences serve their sentences in that jurisdiction and that's my understanding of what the arrangements are," Mr Morrison told reporters.
"No request has been made to Australia for that to be any different."
Australia routinely sends Kiwis who have committed crimes on Australian soil back to New Zealand but only after they have served their prison sentences.
A spokesman for Attorney-General Christian Porter said Australia could only take prisoners from countries defined in a piece of Commonwealth legislation called the International Transfer of Prisoners Act.
"New Zealand is not a 'transfer country' under the ITP Act as it does not have any agreement or arrangement for prisoner transfers with Australia," he said.
Tarrant has been sentenced to life without parole for killing 51 people and injuring 40 others in the March 2019 attacks.
It is the first time a full-life term has been imposed in New Zealand.
Mr Morrison welcomed the unprecedented sentence.
"The world must never see him, or hear from him, ever again," he told parliament.
"New Zealand is family to us in Australia. Today, we send our love across the ditch."
Opposition Leader Anthony Albanese acknowledged the terrorist was "one of ours".
"An Australian who cast such a shadow over our dear neighbour," he said.
Labor frontbenchers Kristina Keneally and Andrew Giles said the man was not simply a gunman, but a violent right-wing extremist and white supremacist.
"Regrettably, we still have not had a serious conversation about how this individual was radicalised or how much of this occurred in Australia.
"But it is clear that at least some of these ugly ideas would have been shaped by conversations and ideas prevalent here."
New Zealand Prime Minister Jacinda Ardern acknowledged the strength of the country's Muslim community who shared their stories during the gunman's sentencing hearing.
"Nothing will take the pain away but I hope you felt the arms of New Zealand around you through this whole process, and I hope you continue to feel that through all the days that follow," she said.
"The trauma of March 15 is not easily healed, but today I hope is the last where we have any cause to hear or utter the name of the terrorist behind it. His deserves to be a lifetime of complete and utter silence."