The Internet has become a crucial battleground in the fight against jihadist propaganda and Western nations need to step up their game, according to participants in a Washington meeting on countering radical groups.

Experts say governments must engage in corporate-style marketing if they are to combat the Islamic State, which is using slick videos to lure foreign nationals to the battlefields of Iraq and Syria.

"If ISIS has a branding and marketing department, where is ours?" said Sasha Havlicek, the founding chief executive officer of the London-based Institute for Strategic Dialogue (ISD).

The think tank has carried out several experiments using Google Ideas, Twitter and Facebook to try to directly engage with potential recruits -- and dissuade them from joining the brutal jihadist movement.

In one campaign, ISD released several videos of Abdullah X -- a fictional character who tries to convince young Muslims that following the Islamic State is not the way forward.

"We were able to 'hypercharge' that content -- inserting him in the very spaces the extremists were using (...) anchoring this content to extremist Twitter accounts, posting it on extremist pages, having it pop out whenever you search for jihad in Syria," said Havlicek.

"And within a few months, this went from reaching 50 people to 100,000 people of our target group of individuals searching to go to Syria for jihad," she said.

The best indicator of success was that ISIS responded by running five pages of "urgent refutation" of the arguments of Abdullah X, she added.

The ISD think tank also launched a pilot project using Facebook to "walk back people from the edge" of extremism by proposing a one on-one chat with people expressing interest in violent jihad.

"Right now, only extremist groups and intelligence services are really engaging with this constituency online," Havlicek said.

The next step is to see "if see if that outreach can be automated," she added.

For that to happen, private companies with well-developed online marketing strategies can offer that knowledge to associations and activists working against the IS message, Havlicek said.

- Counter 'brainwashing' -

The US government is already working to weaken extremist groups online -- a digital blitz involving a State Department team that posts opinion pieces on radical Islam, cartoons and graphic photos.

One senior department official told AFP last year that it was akin to guerrilla warfare.

During the summit, US President Barack Obama urged local communities in America and abroad to take the initiative to protect groups who act in the hopes of "brainwashing young Muslims."

Sessions on Wednesday highlighted existing anti-extremist programs in Boston, Minneapolis-Saint Paul and greater Los Angeles, which involve community policing and other tactics.

The US State Department announced the appointment of a special counter-terrorism communications coordinator, Rashad Hussain, but it was unclear what concrete outcomes there would be.

It is also going to help students around the world to develop digital content that counters the extremist message.

Peter Neumann, the director of the International Centre for the Study of Radicalization, says while everyone done so far to counter extremist groups is "great," it's "only a drop in the ocean."

He said there has been much talk about removing extremist content from the Internet altogether, but that is not a fail-safe solution.