It also acknowledged its soldiers have helped Kurdish forces by directing coalition air strikes.
The officer in charge of the elite special forces, which has been advising local forces in northern Iraq since September, denied that these events represent an escalation of Canada's involvement.
"The situation is a lot more nuanced than just saying, if you exchange fire with a belligerent force then all of sudden it's a combat mission," said Brig.-Gen. Michael Rouleau, commander of special operations command.
"Our ability to bring airpower is one of things we can add value to the Iraqi forces with. Moreover, we always deploy with the inherent right to self- defence. So, we have the right to be able to defend ourselves, if we're fired upon."
He equated it to the sometimes intense firefights involving Canadian peacekeepers during the Balkans mission in the 1990s.
The special forces have, since the end of November, directed 13 air strikes in Iraq, guiding aircraft belonging to the U.S.-led coalition — including a contingent of Canadian CF-18s — to their targets.
That involves being close to the fighting and using sophisticated laser pointers to mark the target for precision-guided bombs.
The briefing Monday at National Defence headquarters peeled back some of the layers of secrecy that have surrounded the special forces mission, which has been almost totally overshadowed by the bombing campaign.
Rouleau acknowledged that Canadian troops have helped Kurdish peshmerga forces plan operations and have visited the largely static First World War-like front to see the situation first-hand.
It was during one of those visits that Canadian soldiers, accompanied by Iraqi forces, came under mortar and machine-gun fire. Rouleau says the Canadians used sniper fire and "neutralized" the enemy positions without taking any casualties.
The special forces troops have also been providing classroom weapons instruction, including the use of mortars and rocket-propelled grenades They also have a small unit of medics and doctors who not only teach battlefield first aid, but have helped treat casualties.
About 80 per cent of the time, the troops are well behind the front line, said Rouleau, who added that he still categorizes the mission as "low risk."
When the up-to 69 special forces troops began deploying, Defence Minister Rob Nicholson insisted before a House of Commons committee that their role was to assist and not take part in the fighting.
"We’re not engaging in combat activity and our role is very specific and very clear," he said.
Nicholson's assurance was backed up a few weeks later by Prime Minister Stephen Harper, who in introducing the Parliamentary motion that sent the CF-18s into battle, said the special forces were in a "non-combat role."
Precisely what sort of assistance they were providing was vague and the best Rouleau was willing to offer at a previous briefing in October was: “We’re helping train them in elements like shoot, move, communicate. How you manoeuvre elements around the battle space, how you can most effectively bring your various weapon systems to bear.”
NDP defence critic Jack Harris says the revelation is troubling.
“For months now, New Democrats have been concerned about mission creep," Harris said late Monday.
"The Conservatives told Parliament there would be no boots on the ground, and now we have confirmation of ground combat and exchange of fire with ISIL. The minister of defence needs to explain why DND doesn’t consider Canadian Forces in combat to constitute a combat mission."
U.S. and Canadian commanders, throughout much of the fall, faced questions about why so few airstrikes had been carried out in support of Iraqi forces, who are battling to eject Islamic state fighters from vast swaths of territory overrun last year.
The notion they were having problems properly identifying targets was well-known and the U.S. recently boosted its special forces contingent and there were suggestions they would help direct bombers to their targets.
The Americans used a similar strategy in Afghanistan in 2001, when Northern Alliance fighters and a handful of special forces operators, backed by air power,routed the Taliban.
A spokesman for Harper drew a line to define what is — and what isn't — combat in the government's view and it involves whether or not Canadian troops are on the offensive.
"A combat role is one in which our troops advance and themselves seek to engage the enemy physically, aggressively, and directly,"said Jason MacDonald. "That is not the case with this mission.
"This mission is one in which they are providing advice and assistance to Iraqi forces only and as the general indicated, the bulk of their work takes place well behind the front lines. That said, we have always been clear that while this is a low-risk mission, it is not without risk and our forces on the ground will protect themselves if fired on in the course of carrying out their mission."
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