Canada is reconfiguring its mission in Iraq to involve training security forces to secure the northern city of Mosul from future terrorist threats, the country's top military commander said Thursday.

Gen. Jonathan Vance, the chief of the defence staff, said the plan hinges on getting buy-in from the new government in Baghdad once it is formed.

That process could take weeks, or even months.

"We're working now on the plans to help set the conditions for a successful return of population to Mosul," said Vance following a speech to the Canadian Global Affairs Institute. "There are still remanents of ISIL there. Not fighting. They're not actively conducting operations, but they could."

The Trudeau government has committed to keeping troops in the war-torn country until 2019, but since the end of major fighting against Islamic State extremists last fall, many have been wondering what the Canadian soldiers would be doing.

NATO intends to expand its training of Iraqi forces and Canada has committed to being part of that, but planning for that work is still in the early stages.

The roughly 200 Canadian special forces troops in Iraq had been helping to train Kurdish peshmerga forces in conventional military tactics to evict Islamic State extremists from Mosul, the embattled country's second-largest city.

The defeat of ISIS on the battlefield last year has seen them revert to a guerilla-style campaign of terror, which requires a different skill set from soldiers responding to it.

Canada suspended its training of both Iraqi and Kurdish forces after fighting broke out last fall in the aftermath of a referendum which saw Kurds voted overwhelmingly for independence.

Making Mosul safe

Vance said training of the peshmerga has ceased entirely, and the focus at the moment is on laying the groundwork for training with Iraqi forces exclusively.

He said it's important for the stability of the country to deal with all of the displaced families.

"Mom and Dad and the kids have got to get home," Vance said. "Mosul is, you know, a population of 800,000 to a million people. We want them to be able to return home and be successful."

A defence expert said the latest undertaking could be precarious and Canadians will need to be more careful than ever not to get caught in the sectarian divide between Shia and Sunni factions.

"To keep Iraq together, you have to have a well-trained, balanced security force," said Steve Saideman, an international affairs professor at Ottawa's Carleton University. "The question at the end of the day is: What kind of security forces are the Iraqis going to build?"

Given how brutally the Sunni were treated under previous Shia-led governments in Baghdad, Saideman said Canadian commanders will be required to do serious vetting of the people they're training to ensure they're not dealing with suspected war criminals.

He said he also doubts about the larger political landscape.

Muqtada al-Sadr, a firebrand, anti-American cleric and militia leader, holds the balance of power. He is Shia, but also a strident nationalist.

On Thursday, he urged his supporters to remain calm after a car bombing killed 18 of his followers.

Saideman said the cycle of violence and revenge runs deep in Iraq.

"I would be suspicious that the Shia, under this government, would be empowered to oppress the Sunnis again, which might cause them to be driven back to an ISIS successor," he said.

​Located 400 kilometres north of Baghdad near the Syrian border, Mosul had a population of 1.8 million and was a relatively thriving centre when it was overrun by ISIS.

Tens of thousands fled during the occupation by both the U.S. and ISIS, and thousands of homes were destroyed in the bloody street-by-street battle that took place throughout 2016 and 2017 to liberate the city.

Canada's mission in Iraq has gone through several iterations.

When the Conservatives were in power, there were CF-18s conducting bombing missions and a small contingent of special forces helping the peshmerga shore up the defences of Erbil, the Kurdish capital.

The arrival of the Liberal government in 2015 saw an end to the bombing campaign, an increase in the use of the highly-trained commandos and the deployment of more intelligence officers.

The mission also has employed, at various times, an air-to-air refuelling plane to top up coalition warplanes, surveillance aircraft to help with targeting, helicopters and a Role 2 combat hospital.