But while he mentioned expanding the current mission, Harper wouldn't say whether that would include Canadian troops going into Syria.
"Next week, it is the government's plan to move forward with a request for Parliament for extension and expansion of the mission. And I will obviously give more details when we do that," Harper said in Mississauga, Ont.
"Let me just say, the current authorization laid open the possibility of going to Syria, although we have not done that. But we'll address issues like that next week when I make a proposal to the House of Commons."
Canada has contributed special forces operators and an air mission in the fight against the Islamic State in Iraq and Syria, also known as ISIS.
The House voted in support of the mission last October, although the prime minister doesn't need parliamentary approval to send troops to battle. Harper has made it a practice to go to the House for a motion of support whenever he approves a mission.
Harper noted the current motion of support from the House doesn't close off the possibility of fighting in Syria.