The Group of Seven (G7) countries and some of the world's biggest technology firms agreed on Friday on a plan to remove jihadi material from the web within two hours of being posted.
"These are the first steps towards a great alliance in the name of freedom," Italian Interior Minister and host Marco Minniti said after a two-day meeting on the Italian island of Ischia off Naples.
Security experts have been warning about the manner in which extremist groups around the world have been efficiently using the internet to radicalize, recruit and train new members.
Britain's Home Secretary Amber Rudd insisted "companies need to go further and faster to not only take down extremist content but also stop it being uploaded in the first place."
The UK, supported by France and Italy, in September urged social media companies to speed up the removal of terrorist content from the internet.
'Malware of terror'
The Group of Seven comprised of Britain, Canada, France, Germany, Italy, Japan and the US also called on tech giants Facebook, Google and Twitter to work with their smaller partners to counter online terror propaganda. It was the first time the technology firms have taken part in G7 talks on this issue.
"IS took to the technology world like a fish to water," said Italian Interior Minister Marco Minniti. He added it was time to unleash an antivirus to fight the terror group's "malware of terror."
Britain's Rudd advocated imprisonment of up to 15 years for those accessing and viewing extremist material on the web, a proposal that Julian Richards, security specialist at BUCSIS (Buckingham University Centre for Security and Intelligence Studies), said would not find favor with other G7 members.
"The UK's fairly hard approach of introducing legislative measures to try to force companies to cooperate ... and suggestions that people radicalizing online should have longer sentences, are often considered rather unpalatable and too politically sensitive in many other advanced countries," he told the Agence France-Presse news agency.
Major technology firms have been developing policies and practices to deal with the menace, but experts say much more needs to be done, especially when it comes to detecting potential threats from home-grown "lone wolves."
In June, Facebook, Google, Twitter and Microsoft launched a "Global Internet Forum to Counter Terrorism" to exchange best practices and engage with smaller companies to check the abuse of the internet by global terrorist groups.
ap/ng (AFP, dpa)