French President Emmanuel Macron offered to help British Prime Minister Theresa May marshal support in the fight against terrorism on Friday, days after a suicide bomber killed 22 people in Manchester.

Axar.az reports citing Reuters.

May, in Italy for her first G7 meeting since becoming prime minister last year, was set to urge the world's major industrialized nations to encourage technology firms to stop militants moving "from the battlefield to the internet".

Jihadist attacks have killed more than 230 people since 2015, and Macron said he would work with Britain to prevent internet firms "publishing Islamic State propaganda", a French diplomatic source told Reuters.

"We know this kind of attack," the newly elected president told May at the San Domenico Palace Hotel, a former monastery in Taormina, Sicily.

"We will ... do everything we can in order to increase this cooperation at the European level, in order to do more from a bilateral point of view against terrorism. We will do that during the whole day, because that’s the common challenge."

Sitting in front of the flags of France, Britain and the European Union, May said she was looking forward to wider discussions at G7 "on how we can work further to defeat the terrorists".

While Italy hopes the G7 meeting on the cliffs of eastern Sicily will concentrate minds on Europe's migrant crisis, the British leader wants to set out her stall on measures to tackle the promotion and facilitation of radical ideologies on the internet.

"The PM will say that the threat we face is evolving, rather than disappearing, as Daesh (Islamic State) loses ground in Iraq and Syria. The fight is moving from the battlefield to the internet," a senior government source said on Thursday.

"If you have unity at the G7, and you are all sending out the same message, that we want internet companies, social media companies to step up ... then obviously that delivers a powerful message."