Prime Minister Justin Trudeau says the federal government has confidence in the RCMP to investigate Canadians who travelled to fight alongside extremists in Iraq and Syria.

Speaking in France following a D-Day anniversary ceremony, Trudeau said the Mounties and intelligence agencies in Canada and abroad face the difficult challenge of presenting the information they gather in court as evidence of crimes.

Trudeau says the government is ensuring Canadian agencies have the necessary resources and opportunities to collaborate with foreign allies on such cases.

The latest annual federal report on extremism says some 190 people with connections to Canada are suspected of terrorist activity abroad and, in addition, approximately 60 have returned.

The activities of these Canadians in various countries could involve front-line fighting, training, logistical support, fundraising or studying at extremist-influenced schools.

A small number of the 60 returnees have come back from Turkey, Iraq or Syria, and many who went abroad now lack valid travel documents, find themselves on a no-fly list or fear being arrested on Canadian soil.

"We fully respect the role of the RCMP to make determinations independently on how it will proceed with prosecutions with its approach in various investigations. We have confidence in the RCMP," Trudeau said.

"One of the challenges when it comes to international issues of this sort is always making the translation from intelligence-gathering activities to presenting evidence of crimes," he added. "That is something that the RCMP, our intelligence agencies, and indeed agencies around the world, are struggling with and working on very hard."

The RCMP says relationships with foreign police are fundamental to Canada's ability to deal with extremist travellers.

"While our ultimate goal is criminal prosecution, we look at every tool at our disposal to disrupt the threat," said Cpl. Caroline Duval, an RCMP spokeswoman.

Public Safety Minister Ralph Goodale has stressed that Canadians who travelled to join overseas extremists chose to abandon the democratic advantages of Canada in favour of pursuing terrorist activities.

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