The leaders of New Zealand and France plan to host a meeting of global leaders and tech executives in an effort to stamp out the transmission of violent extremism on social-media sites.

Meetings over two days in Paris next month will take place alongside a Group of Seven meeting of digital ministers and a separate technology summit, New Zealand’s government said Wednesday. Prime Minister Jacinda Ardern said she and her co-chair, French President Emmanuel Macron, would seek a pledge from attendees to end the use of social media...