G7 Demand Action on Extremist Net Content at Summit
They warned internet service providers and social media companies to “substantially increase” their efforts.
But the summit in Taormina, Sicily, failed to agree on climate change.
US President Donald Trump, attending his first such summit, held off from endorsing the 2015 deal on reducing greenhouse gas emissions.
Separately, Mr Trump and UK Prime Minister Theresa May reaffirmed plans to boost trade, including a post-Brexit trade deal.
Mr Trump has welcomed the UK’s vote to leave the European Union (EU).
Mrs May was also attending her first G7 summit, as were Italian Prime Minister Paolo Gentiloni and French President Emmanuel Macron.