Prime Minister Jacinda Ardern will raise the harm that comes from chasing profits with tech companies at the Christchurch Call in Paris.
But on the eve of the first event leading to the summit, it has suffered a potential setback as there is still no sign that the United States will take part.
US support for the Christchurch Call will be particularly crucial to give it a strong mandate, especially as many of the tech companies are based there.
Ardern landed in Paris today (NZT) where, as well as this week's summit, she will also have bilateral meetings with leaders who are expected to sign the call, including UK Prime Minister Theresa May and Canadian Prime Minister Justin Trudeau.
But her focus will be on Thursday's (NZT) summit, where the leaders of governments and tech companies will come together for the first time to commit to blocking terrorist content and violent extremism from social media platforms.
It will be a voluntary framework aimed at preventing such content from being uploaded in the first place, and then stopping it going viral if preventative measures fail.
Ardern said the correlation between the companies' profit-motive and harmful content will be discussed, even though the companies are unlikely to want to share the algorithms they use to boost revenue.
"Making that ask, then immediately you get the wall of commercial sensitivity," Ardern said.
"But we've got to have the conversation around whether or not commercial imperatives are driving certain behaviours that are ultimately harming people.
"The companies know we're going to raise that issue, but they're coming and we'll start that discussion here."
This echoes a statement she made to Parliament on the first sitting day after the March 15 attack that ultimately claimed 51 lives, when she said: "There cannot be a case of all profit, no responsibility."
Ardern told the Herald last week that US President Donald Trump was not coming to the summit, but the US might still send a representative.
But with the first event - a meeting with civil society and tech-interested parties - taking place tomorrow, US attendance is still up in the air.
"We have been in dialogue with all of the G7 nations. I don't wish to confirm or otherwise on the United States until we know for certain whether or not there will be representation there," Ardern said.
She remained hopeful that a US representative would be at the summit, and if not, that the US would eventually sign on.
One concern from the US is whether signing the Christchurch Call might infringe on first amendment free speech rights.
US law also takes a softer stance on social media platforms, providing immunity from liability for the content they host.
Eight countries and the European Commission will be represented at the summit. Two more countries, including Australia, will not be but will sign up to the Christchurch Call, the Herald understands.
Ardern said the call would set a standard for certain outcomes and then expect tech companies and governments to adopt policies to enforce those standards.
"This action plan will not be prescribing what kind of domestic legislation that countries will set, but it does have an expectation that they will address terrorist content in their own jurisdiction," Ardern said.
Like the US, New Zealand law provides immunity from liability to social media platforms if they follow a certain complaints process.
New Zealand law also does not specifically address online terrorist or violent content, and Ardern said work was under way to look into whether it should.
The UK is considering a paper that suggests taking down a site that is hosting violent material, but Ardern would not say if that might be part of changes to New Zealand law.
How to deal with controversial internet forums such as 8chan will also be looked at; 8chan was blocked by ISPs because it was being used to broadcast the gunman's video.
Substantial fines are also missing from New Zealand's Harmful Digital Communications Act, but Ardern noted that fines would not have prevented what happened on March 15, when the gunman's video went viral.
"We know the harm and the proliferation of that video was rapid, so our test is: would it have made a difference in our experience?"
She said the call would be stronger than the Global Internet Forum to Counter Terrorism that was set up in 2017 by Facebook, Youtube, Google and Microsoft.
"We are, I believe, lifting expectations, but also the fact that we have a wide range of governments and leaders at the table alongside tech companies, rather than it simply being tech companies themselves driving a solution."