Prime Minister Jacinda Ardern says the Christchurch Call summit in Paris is about blocking violently horrific content from being uploaded to social media sites, as well as stopping it going viral.
And though the summit will not result in globally enforceable rules, she says it will be valuable if the likes of Facebook commit to a preventative approach, rather than continuing to respond long after the damage is done.
"Government responses are reactive. They are all around take-down, whether you have an hour or 24 hours," Ardern told the Herald in an interview before flying to Paris last night.
"When you have something going viral that quickly, the harm is already done. The things that are enforceable [such as government regulation] wouldn't have helped in Christchurch.
"The responsibility can't just fall on governments. If we want to prevent a Christchurch from happening again, we actually need commitments from the tech companies."
Prompted by the attack that claimed 51 lives, the Paris summit will seek an agreement with countries and tech companies to prevent terrorist content or violent extremism from being hosted on social media platforms.
But there is no international body that the tech companies answer to, raising questions around whether the summit will yield anything meaningful if they simply don't do what they sign up for.
Ardern has confirmed it will be voluntary framework.
Social media platforms already have standards that ban such content, and have hardly earned a reputation as beacons for social responsibility; Privacy Commissioner John Edwards even went as far as calling Facebook "morally bankrupt, pathological liars".
Facebook boss Mark Zuckerberg, who is not attending the summit, has previously called for governments to regulate what material should be banned, which would guide Facebook in building a preventative system to achieve that.
In the absence of a global regulatory regime, Ardern is hoping the summit will lead to a call to action that will result in the same outcome.
"What model would you like to apply here? The [non-existent] international criminal court for social media? It would still be reactionary," Ardern said.
"That's why we're trying to get in front of this problem. It's not easy, but the alternative was just simply accept what happened on the 15th of March and say it was too hard to fix."
One of the issues is artificial intelligence (AI) technology, which Facebook has said is not advanced enough to block video content similar to the gunman's as it is uploaded.
Getting companies to pledge a commitment to innovate is part of the Paris discussion, Ardern said.
"In the preventative space, if we want companies to devise technological solutions, that's the kind of thing that's going to generate it. You can't regulate a company to innovate, which is actually what we need them to do.
"Before sitting down with leaders and tech companies [at the summit], there is a session being chaired by the King of Jordan and myself with tech companies where the question will be: where can technology take us to help us answer some of these questions?
"We might not have all the answers now, but we actually can set a path to commit to trying to find them."
Several countries, including New Zealand, have domestic laws designed to minimise online harm, but there is confusion over which jurisdiction applies to which aspects of social media, due to the platforms' vast global reach.
For that reason, Ardern has sought a global initiative since the terror attack.
"The fact it was designed to go viral, the fact it was uploaded 1.5 million times on Facebook, one upload per second on YouTube - that was new," Ardern said.
"In New Zealand alone, we had 8000 calls to the 1737 [mental health] line, people identifying that they'd seen the video and it so deeply disturbed them that they were calling."
The obvious question was what could be done to prevent it happening again, she said.
"We could do that domestically with gun law reform, but we couldn't on social media. We needed a global solution, and one that was preventative."
Asked how the call to action from the Paris summit would have any teeth, Ardern said: "Until it's signed, there's still work going on."
But she said even words of good intent, signed by multiple countries and companies, are valuable.
"Actually saying there is a moral responsibility on the companies as much as there is on governments is important.
"[But] we are seeking action. Are we pulling everyone together for a conversation? No. These leaders, their time is too important for that.
"And we need to apply our collective pressure to those who have the solutions within their power."
Ardern will have three key meetings in Paris: one with internet and technology stakeholders, one with tech company leaders, and the summit on Thursday (NZT) with tech company leaders and heads of state.
The leaders of seven countries, including UK's Theresa May and Canada's Justin Trudeau, will attend, as well as representatives from Facebook, Google, Microsoft and Twitter.
Broad buy-in will be crucial, and Ardern said it was a good turn-out given the short timeframe, despite the absence of US President Donald Trump and Facebook boss Mark Zuckerberg.
Internet NZ chief executive Jordan Carter, who will chair the stakeholders' meeting in Paris, said the call was about enforcing the rules that social media companies already had.
"It's not asking for them to do anything they haven't already said they would do. It's saying, 'Where's the delivery, folks?'
"All the main platforms have been rapidly growing machine-learning and AI tools to deal with it. I assume some of the discussion will be about how much more they can do on that front.
"If you're making a principled commitment to get this stuff off your platform, there's then got to be a story about how they're going to do that for it to be credible. Then there's going to have be some transparency on how they're doing."
Ardern said whatever comes from Paris will be an evolving document.
"Technology will keep changing. The way these platforms are utilised will keep changing. We will need to keep adapting and getting in front of those changes. It's a model going forward on how we want to work and engage together as well.
"One of the reasons we have focused on extreme violent terrorist content is because there is no freedom of expression argument there. No one has a right to broadcast murder."
• What? The Christchurch Call summit in Paris on Thursday (NZT), chaired by Jacinda Ardern and French President Emmanuel Macron
• Why? Following the terror attack on March 15, the aim is to seek a commitment from country leaders and tech companies to stop terrorist content and violent extremism on social media platforms
• How? Not by reactionary means, such as government regulation, but by preventative means, such as a pledge to develop more advanced technology to block unsuitable content as it is uploaded
• Who? Facebook, Microsoft, Twitter, Google, Amazon representatives are going, as well as seven country leaders including the UK's Theresa May and Canada's Justin Trudeau. No-shows from US President Donald Trump and Facebook boss Mark Zuckerberg.