The Christchurch Call summit in Paris will be the culmination of weeks of effort from Prime Minister Jacinda Ardern, underpinned by the warm relationships she nurtured with world leaders last year.

On the eve of the national memorial service two weeks after the March 15 terrorist attack, Jacinda Ardern had a phone call with German Chancellor Angela Merkel to discuss how to curb social media harm.

The New Zealand Prime Minister had met Merkel in Germany last year on a trip seeking support for a New Zealand-European Union free trade deal, an encounter Merkel described in jovial terms