Nicholson travelled to Baghdad and northern Iraq's capital of Erbil for meetings with Kurdish leaders this week.
During a conference call from neighbouring Jordan, he told reporters that the threat of ISIL dominated his conversations in the Middle East.
While in Baghdad, Nicholson said he discussed the ongoing fight against the Islamic State.
"I took the opportunity to express Canada's support for political reform and good governance," Nicholson said.
"I commended the Iraqi government for the progress they've been making to date, though I recognized that much remains to be done for the Iraqi people to gain the freedom, security and stability that they deserve."
Devastation in Erbil 'truly appalling'
In Erbil, he said he "saw first-hand the devastation brought on by [ISIS]," which he described as "truly appalling."
But he declined to provide additional details on the possibility of Canada extending its air mission, which is set to expire at the end of March.
"One of the reasons that I am here is to get information with respect to all aspects of our contribution," he said.
"The government will be making a decision on this in the next few weeks."
While he acknowledged that the current mandate will expire early next month, Nicholson said the government is "looking at ways that we have contributed, and what is available for the future."
"Canada is not a country that stands on the sidelines," he said.
"We are in this for the longer term to make sure we do what we can to help."
He added that so far, the feedback he got on the ground was that Canada's support "has been very helpful and very much appreciated."
Nicholson also travelled to the United Arab Emirates this week after a previously-publicized stop in Paris.
He told reporters that global security was at the top of the agenda during his visit to Paris.