Prime Minister Stephen Harper laid out his proposal Tuesday to extend the current combat mission until March 31, 2016 during a speech to the House.
It would also give Canadian Forces authorization to mount airstrikes in Syria.
"As far as ISIS is concerned, there is no Iraq-Syria border," Defence Minister Jason Kenney told CBC News Network host Heather Hiscox on Wednesday morning.
But he stressed that Canada has "no interest in getting involved in the Syrian civil war, in any shape or form."
Kenney was initially slated to appear alongside Nicholson at the briefing, but his lectern was removed from the stage shortly before the briefing was set to begin.
Both the New Democrats and the Liberals have indicated they will vote against the motion, in part because they believe Canada should focus its efforts on humanitarian and diplomatic measures in the fight against the so-called Islamic State in Iraq and Syria.
No additional aid plans are expected to be revealed at today's briefing for journalists.
Later today, senior government officials will brief MPs during a closed-door session on Parliament Hill.
The motion is scheduled to be debated on Thursday.
Vote not required
Although the prime minister has made it a hallmark of his government to give MPs the opportunity to debate and vote on proposed military missions, parliamentary consent is not actually required to deploy Canadian troops. That authority rests exclusively with the executive, which exercises it on behalf of the Crown.
In an essay published last fall, University of Ottawa professor and defence expert Philippe Lagassé noted that such votes can be seen as a "courtesy" extended to MPs by the executive.
"The votes allow MPs to express themselves on a matter of national importance," he pointed out.
"In addition, they can be seen as a means of assuring the military that their mission has the support of the elected house of Parliament, and the votes add an aura of democratic legitimacy to controversial policy decisions."
But it can also provide political cover for the governing party, he adds.
"By laundering these decisions through the House, the government gives the impression that the Commons shares responsibility for the deployment."