With operations against ISIS at a critical stage in northern Iraq, Defence Minister Harjit Sajjan announced Friday that Canada will extend its training mission there by three months.

The Canadian Forces will continue operations until June 30, providing "the time required to assess the evolving nature of the fight."

Canada is part of a coalition working with Iraqi troops to recapture territory taken over by the Islamic State in Iraq and Syria (also known as Daesh), restore basic government services and enable citizens who fled to return to their homes.

A news release said the scope and mission of Canada's contribution, often characterized as an "advise and assist" operation, will remain the same this spring, "with a few adjustments."

"As a result of recent successes in the campaign, some elements of the Canadian Special Operations Task Force have recently been operating in eastern Mosul, providing advice and assistance to Iraqi Security Forces," it read.

"Canadian troops remain behind the forward line of troops, and are providing advice and assistance to Iraqi Forces," the government said.

Canadian troops had been stationed around Erbil, where its operations had included a military hospital.

'Canadians should expect further adjustments'

But the fighting in and around Mosul has been intense recently, as the fight to retake control over the strategically important city continues.

"While the geography and partners have expanded, the mandate of training, advising, assisting, and equipping remains unchanged," a statement from the chief of the defence staff, Gen. Jonathan Vance, said.

"The mission may change further as the situation evolves and Canadians should expect further adjustments as the situation warrants."

"It is clear that coalition efforts are having a real impact on the ground," Sajjan said in the release.

Hundreds of reconnaissance missions

The military said Friday that 3,600 personnel have been part of rotations for the mission so far. As of March 28, Canadian aircraft who remained in theatre after Canada's CF-18s returned home have conducted 695 aerial refuelling sorties and 753 reconnaissance missions.

In addition to the special forces soldiers acting as intelligence officers and training Iraqi soldiers on the ground, Canada has also contributed tactical helicopters to the coalition mission.

Canadian special forces soldiers, left and right, speak with Peshmerga fighters at an observation post last month in northern Iraq. (Ryan Remiorz/Canadian Press)

Speaking to reporters after attending a change-of-command ceremony, Vance defended the decision to only renew the mission for three months.

"This prolongation of the mission for three months gives us an opportunity to look more closely at what the wider changes may be in the theatre," he said. "It allows us to carry on the mission more or less as it has been for the last two years but also allows us to make the adjustments necessary as the situation changes."

Friday, the military revealed that Canadian soldiers were operating in part of Mosul. Vance said the Canadian soldiers only moved into east Mosul once it was secured.

"They are doing exactly the same task they were before. The geography changed somewhat and the partners changed somewhat. That is, we went from mentoring, training, advising Kurds to other Iraqi security forces."

Vance said Canadian forces have been ensuring that coalition forces continued to hold east Mosul while the battle moved to western Mosul.

Vance says mission on track

Vance said the coalition has been achieving what it set out to achieve.

"I think the coalition has done what it set out to do thus far and is on track, [as much] as anything this fluid and complex can be on track, in Iraq. We set out to stop Daesh. They were stopped. We set out to reverse their gains. Those have been reversed in huge measure. And now we are into the detailed fight of getting them out of their command-and-control centres in Mosul and, of course, in Syria in the city of Raqqa."

Vance's comments also come as the United States is pressuring its NATO partners to increase their spending on defence, arguing the U.S is picking up a disproportionate share of the tab. Friday, U.S. Secretary of State Rex Tillerson warned NATO allies to spend more on defence or come up with a plan within two months to reach the military alliance's budget guideline of two per cent of GDP.

Vance said people should wait for the results of the government's upcoming defence policy review.

"We're fortunate that we have a defence policy review that is just about complete and the government is a few weeks away from announcing it. When that is announced, I think that is the best time to judge what the investment is into the armed forces and determine what we look like going forward into the future."