Jacinda Ardern is highlighting the importance of the Christchurch Call in the wake of a shooting in Germany that was live streamed online.
The Prime Minister said after the March 15 Christchurch shootings, which were also live streamed, there was "every chance that kind of streaming of such a horrific even could happen again".
She said that's why the Christchurch Call to Action was "put in place" - a pledge by governments and technology companies to work towards eliminating harmful content online.
- Two shot dead near synagogue in Germany
- Christchurch Call: 16 countries, eight tech giants sign up
- Facebook's Mark Zuckerberg snubs another Christchurch Call meeting
The shooting took place in the German town of Halle on Wednesday night (NZ time), where two people have been killed in separate shootings, one outside a synagogue.
The shooter live streamed the attack on the gaming site Twitch which is owned by US multinational technology company Amazon, which recently signed up to the Christchurch Call.
The pledge includes a crisis-response framework for tech companies and governments to work together to prevent the spread of terrorist or violent content online.
Ardern said she was pleased to see that the "incident protocol that we've developed has kicked in, [and] companies are communicating with one another, to ensure that this video does not spread online".
She said the next thing to focus on is "technological development and research that's needed to prevent it from happening in the first place".
"We've all acknowledged that's work that is still ongoing, but I think this demonstrates why it is so necessary and why that work must continue... It shows why we need to work with those technology companies."
Twitch was one of the platforms that broadcast the Christchurch terrorist's attack video live, and later apologised in a statement in May saying it was working to remove "offending content" and related accounts.
The latest horrific livestream on its platform has been deemed illegal in New Zealand by Chief Censor David Shanks, under the Films, Videos & Publications Classification Act 1993.
"While this video is not filmed in New Zealand and fatalities are fewer than in Christchurch, the fundamentals of this publication are the same as that of the March 15 livestream," Shanks said on Thursday.
"It is clearly promotional and crosses the line in terms of New Zealand law as it depicts extreme violence and terrorist atrocities."
The Chief Censor said an urgent process is currently underway to finalise a detailed report of his decision, which will be released as soon as it is available.
"While this terrorist has killed fewer people the video will still be seen as instructional in terms of learning from it in order to carry out other attacks."
Ardern said she does not underestimate the scale of that challenge for world leaders in trying to stop people from uploading this type of material online.
But she said there is "space for that development to occur, and that's ultimately where we need to also focus our attention".
"Now the work that needs to be done is that preventative work."