Sixteen countries and eight of the technology industry's biggest firms and websites have joined a New Zealand-led effort to eliminate terrorist content from the internet.
But the US - home to many of the world's biggest tech firms and websites - is not among them.
France, Canada, Indonesia, Ireland, Jordan, Norway, Senegal, the UK, Australia, Germany, Japan, India, the Netherlands, Spain and Sweden have signed onto Prime Minister Jacinda Ardern's Christchurch Call at a summit in Paris.
So have the European Commission, Amazon, Facebook, Dailymotion, Google, Microsoft, Qwant, Twitter and YouTube.
"We can be proud of what we have started with the adoption of the Christchurch Call," said Ardern. "We've taken practical steps to try and stop what we experienced in Christchurch from happening again."
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- Warnings about threat from white supremacists were ignored
Fifty-one people were killed by an alleged white supremacist gunman on March 15 when he opened fire in two Christchurch mosques. He posted a manifesto online shortly before the atrocity, which was livestreamed on Facebook.
"The sheer scale of its reach was staggering," Ardern told world and tech leaders gathered in Paris on Wednesday (local time).
"The original footage was viewed 4000 times before being removed by Facebook. But within the first 24 hours it spread and proliferated, 1.5million copies of the video were taken down from Facebook. There was one upload per second to YouTube in the first 24 hours alone.
"It's hard to quantify the harm this caused. But the fact it caused harm is unquestionable. Thousands of New Zealanders called our nationwide mental health support line saying the video was causing them distress."
Ardern said the video continues to be uploaded online, supporters of the despicable act editing the video to try and avoid algorithms designed to detect and prevent it.
"I know that none of you want your platforms to perpetuate and amplify terrorism and extremist violence," Ardern told tech leaders.
"But these platforms have grown at such pace, with such popularity, that we are all now dealing with consequences you may not have imagined when your company was just a start-up. Your scale and influence brings a burden of responsibility.
"I know what we are doing isn't simple, and that our goal - of eliminating the upload of this kind of content is ambitious - but it is also necessary... We ask that you enforce the standards and policies you already have against this kind of content."
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Ardern also told world leaders they need to "think beyond our national borders and work globally and collectively".
"Our societies must be compassionate and inclusive no matter what religion, race or gender, and we cannot call for others to model this behaviour unless we model it ourselves, in our actions and in our language.
Online, we as governments may choose regulation as a tool to address this issue. But we need to recognise that regulation alone will not solve the problem. We need to work collectively - with tech companies, with civil society - to make meaningful change.
"And where we regulate, these regulations must not become a barrier to a free, open and interoperable internet. We must maintain and support an internet that acts for good."
US supports, but won't sign
A notable exclusion from the initial nations signing up to the Christchurch Call is the US, where many of the world's biggest websites and tech companies are based, including Facebook.
In a statement, the White House said it supports the "overall goals" of the effort, but "is not currently in a position to join the endorsement" - instead saying it preferred a path of "promoting credible, alternative narratives as the primary means by which we can defeat terrorist messaging".
"We will continue to engage governments, industry, and civil society to counter terrorist content on the internet."
The First Amendment to the US Constitution guarantees free speech, and officials fear the Christchurch Call might breach that.
Facebook, Amazon, Google, Microsoft and Twitter released a joint statement saying it was "right that we come together, resolute in our commitment to ensure we are doing all we can to fight the hatred and extremism that lead to terrorist violence".
"Terrorism and violent extremism are complex societal problems that require an all-of-society response. For our part, the commitments we are making today will further strengthen the partnership that Governments, society and the technology industry must have to address this threat."
The five companies included a nine-point plan to achieve this, including:
- increased checks on who can livestream and who can't
- publishing regular reports on how much terror content they've had to remove
- making it easier to report terrorist content
- working together to improve AI and processes on spotting terrorist content
- combating hate and bigotry.
The full plan is available on Facebook's Newsroom blog.
Ardern says she plans to shop the Christchurch Call around to more countries and tech firms.
"For anyone, but especially those concerned that this action plan we are endorsing today is about curbing freedom of expression, let us be clear; an open, free and secure internet delivers extraordinary benefits to the world.
"Ensuring that fundamental freedoms, including freedom of expression, are not compromised underpins the Christchurch Call."