The leaders of the world's most powerful nations are likely to have been invited to the "Christchurch Call" meeting in Paris next month for the Christchurch Call summit, co-chaired by Prime Minister Jacinda Ardern.
While Ardern declined to name any leader who had confirmed attendance, she said there would be "a core group of leaders".
"We will look to announce final details on that closer to the time," she said at her post-Cabinet press conference today.
Since the March 15 terrorist attack in Christchurch that killed 50 people and was livestreamed on Facebook, Ardern has been working towards a global initiative to stop social media platforms from being used to promote terrorism and violent extremism.
The meeting next month will take place in Paris on May 15, and will be co-chaired by Ardern and French President Emmanuel Macron.
It will be held alongside the "Tech for Humanity" meeting of G7 Digital Ministers and France's separate "Tech for Good" summit, both on May 15.
It is likely that about 10 world leaders will attend the Christchurch Call summit, along with top-tier representatives of the world's biggest tech companies.
The leaders of G7 nations are likely to have been invited, including the USA's Donald Trump, the UK's Theresa May, Canada's Justin Trudeau, Germany's Angela Merkel, Italy's Paolo Gentiloni and Japan's Shinzō Abe.
Ardern has already spoken to Facebook's Mark Zuckerberg and Sheryl Sandberg, Twitter's Jack Dorsey, Apple's Tim Cook, Google's Sundar Pichai and Microsoft's Brad Smith.
The text of the Christchurch Call agreement is currently under negotiation, and questions have been raised about who will sign up and how effective it will be.
Ardern has said preventing online terrorism was not about limiting freedom of expression.
"I don't think anyone would argue that the terrorist on the 15th of March had a right to livestream the murder of 50 people.
"We all need to act, and that includes social media providers taking more responsibility for the content that is on their platforms.
"It's critical that technology platforms like Facebook are not perverted as a tool for terrorism, and instead become part of a global solution to countering extremism."
She said the summit would not mark the end of the issue of extremism online.
"We will be looking over a period of time to try and bring on board as many countries and companies as we're able."