Open internet advocates are backing the government's 'Christchurch Call' for change on social media

Jacinda Ardern will ask overseas governments and companies to sign up to the pledge to stop the spread of terrorist content online.

It will happen at a meeting of world leaders and tech bosses in Paris next month.

Internet NZ CEO Jordan Carter says the pledge's success will be down to its narrow focus.

He says a global call with some common approaches will help countries introduce laws that make it easier to comply.