Leaders from the group of leading industrial nations, the G7, have called on internet giants to crack down on extremist content. They warned internet service providers and social media companies to substantially increase their efforts.
The leaders signed a document saying more should be done by internet companies to identify and remove extremist material. 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.
Mrs May was also attending
her first G7 summit, as were Italian Prime Minister Paolo Gentiloni and French President Emmanuel Macron. The G7 consists of Canada, France, Germany, Italy, Japan, the UK and the US, while the EU also has representatives present.
The leaders also voiced solidarity with the UK after Monday's bombing in Manchester in which 22 people, including children, were killed. The US President and Japanese Prime Minister Shinzo Abe discussed the nuclear and missile threat from North Korea.
They agreed to enhance sanctions on North Korea, including by identifying and sanctioning entities that support North Korea's ballistic missile and nuclear programmes.
Today, the second and final day, the leaders are expected to discuss human mobility, food security and gender equality.