The G7 meeting comes days after US-backed forces took the Syrian city of Raqqa back from IS.
Despite the breakthrough, British security services warned this week that the terror threat in the UK is higher than ever.
"This pace, together with the way extremists can exploit safe spaces online, can make threats harder to detect," Britain's spy chief Andrew Parker said Thursday, following a spate of attacks that have killed 36 people in the UK this year.
"I've heard a lot of times the definitive fall of Raqqa," Middle East expert Julien Theron told RFI on Thursday.
"We have to remember that more than one year and a half ago, Isis said it would accept the fall of Raqqa, Mosul and Sirte and that it would go underground again. So territorial loss of Isis doesn't mean the end of Isis."
It may be too early to celebrate the victory of the de facto capital of IS's "caliphate", he says.
And perhaps too soon to discuss counter-terrorism with the ticking timebomb of ex-fighters who are likely to return to their countries of origin.
The last time G7 ministers met in May, in Taormina on the Italian island of Sicily, Britain was still reeling from the effects of the bombing of a pop concert in Manchester. That attack, they said, underscored their need for closer cooperation in countering the terror threat.
"The internet plays a decisive role in radicalisation", said Italy's Interior Minister Marco Minniti, who is hosting the summit in Ischia off Naples. "Over 80 percent of conversations and radicalisation happen online."
The two-day meeting was to look at ways of better policing internet content, as well as sharing intelligence to prevent the fallout from returning fighters.
Cutting off terror groups access to the internet and limiting potential recruits' exposure to propaganda is what G7 ministers are proposing, but this strategy poses a whole host of challenges.
"Part of the problem is the volumes of material that gets shared on YouTube, not just extremist material but all of it which makes it hard to police," cybersecurity expert Robert Pritchard told RFI.
In a first for a G7 meet, representatives from Google, Microsoft, Facebook and Twitter, will take part in the talks with the seven ministers from Britain, Canada, France, Germany, Italy, Japan and the United States, to discuss how the internet can be used to tackle terrorism rather than promote it.
"I think there's more that they can do technically but they just haven't been incentivised to do it so far," continues Pritchard, adding that the tough US laws were also impeding results.
"They're multi-jurisdictional. Europe has much tighter laws than the US for instance where it's not illegal to propagandise and they have the First Amendment to protect free speech."
Some internet firms have started using software to automatically detect content judged extremist and snuff it out, a move that comes off the back of the launch of the Global Internet Forum to Counter Terrorism backed by the G7 in June.
Tackling the cause
But the internet is not the key question, reckons former counter-terror detective David Videcette.
"We need something that's in the middle, we need to start looking at why these people are travelling," he told RFI.
"Yes, the internet is a problem but it's not the internet that puts you on a plane to Turkey and then smuggles you across the border and onto a battlefield in Syria. Certain communities, certain mosques, encourage the caliphate, extremism and they encourage people to travel."
If the G7 ministers want to find a lasting solution, they must think outside the repressive box, he argues, and tackle the root causes of terrorism in their own countries.