Malcolm Turnbull has defended the decision to deport Kiwi criminals to New Zealand during a meeting with the country’s Prime Minister Jacinda Ardern.

Speaking to reporters outside Kirribilli House in Sydney on Friday after bilateral talks on Pacific cooperation, Ms Ardern and Mr Turnbull talked up the close relationship the two countries share – despite agreeing to disagree on deporting criminals and nuclear weapons.

When asked about the morality of Australia deporting convicted criminals back to New Zealand, despite some never having lived across the Tasman, Mr Turnbull said the process was a fair and just one”.

“The answer to your question is “‘yes,” Mr Turnbull said, making it clear the policy would not change.

“This is in accordance with Australian law, and the process is “a fair and just one,” he said.

Ms Ardern responded that while she accepted the fact Australia was “well within their rights” to exercise the deportation policy, she had brought up the issue once again, reported the ABC.

“I have raised again, as we have on previous occasions, elements of the deportation policy where, for instance, someone has never stepped foot in New Zealand.

“We have been keen to make sure the Australian government is aware of our perspective on that and our strength of feeling, but ultimately it is in the Australian government’s hands to determine how they manage that element of the policy.”

As of late January, there were 170 New Zealanders, including 17 women, in Australian immigration detention whose visas were automatically revoked following a December 2014 crackdown on foreign-born convicted criminals.

Foreigners who have served more than 12 months in Australian jails have been steadily rounded up for deportation.

Mr Turnbull said it didn’t just apply to New Zealanders but all foreign-born criminals.

Nuclear weapons treaty ‘flawed’

New Zealand is seeking an early ratification of a United Nations nuclear weapons treaty ban, which Australia has refused to sign.

Mr Turnbull maintains the treaty is flawed because it doesn’t cover the world’s nuclear powers — the United States, the United Kingdom, Russia, France, China, India, Pakistan and North Korea.

He said Australia also relies on the deterrent protection from the United States’ nuclear weapons arsenal.

“Everyone would like to aspire to a world which is free of nuclear weapons but we have to focus on the here and now,” Mr Turnbull said, adding Australia is committed to working towards non-proliferation.

New Zealand has long held a firm line opposing development of nuclear capabilities, which at times puts it at odds with allies.

Ms Ardern said her country’s stance enhanced its credibility on the North Korean nuclear threat.

“It’s become part of our identity as a nation,” she said.

Turnbull wants to concentrate on US refugee deal

Meanwhile, Mr Turnbull says Australia will consider “other options” for refugee resettlement once its transfer deal with the United States is complete.

Mr Turnbull thanked Ms Ardern for restating her country’s offer to take refugees from offshore detention, but added Australia would focus on completing the “much larger” arrangement with the US.

“We will do that, we will take that process through to its completion, and then we will consider other options,” Mr Turnbull said.

It’s not the first time the two leaders have discussed the proposed refugee-swap arrangement.

In November last year, the offer was put on the table by Ms Ardern to take 150 refugees a year from Australia’s off-shore run detention centres.

She told reporters at the time that “no matter what label you put on it there is absolute need and there is harm being done”.

“I see the human face of this, and I see the need and the role New Zealand needs to play. I think it’s clear that we don’t see what’s happening there as acceptable – that’s why the offer’s there.”

Despite their differences on Friday, the two leaders were keen to talk up the “enduring” partnership between the two countries.

Ms Ardern said there was “no greater ally to New Zealand than Australia”.

“That can be seen through our economic links, our economies, the most integrated in the world,” she said.

Mr Turnbull responded by saying their meeting “demonstrates the strong and enduring partnership between Australia and New Zealand”.