Macron and Ardern established the Christchurch call in 2019, as a response to a violent attack in Christchurch, urging world leaders and tech companies to take greater action against terrorism and online extremism.
This year's summit comes following the death of French teacher Samuel Paty, who was beheaded outside his school in a Paris suburb in October 2020.
"This cannot and should not happen again," Macron said, attending the summit virtually, from the presidential residence in Bregancon Fort in southern France.
On March 15, 2019, New Zealand was left reeling after a lone gunman targeted two mosques in Christchurch, killing 51 people while streaming the massacre live on Facebook.
"The existence of algorithms themselves is not necessarily the problem, it's whether or not they are ethically used. That is one of the biggest focus for the community over the next year alongside expanding the network itself," Ardern said at a news conference after the forum.
Facebook, the world's largest social network with 2.7 billion users, consequently came under fire for failing to react quickly enough to the livestream which lasted approximately 17 minutes, and for not doing enough to tackle extremism.