"We do not stand on the sidelines and watch. We do our part," Harper made the comments following a meeting with European Union leaders on Parliament Hill on Friday.
"That's always how this country has handled its international responsibilities, and as long as I'm prime minister that's what we will continue to do."
Harper's comments come ahead of an expected meeting with his cabinet next week to discuss deploying Canada's CF-18 fighter jets to join a U.S.-led campaign against the Islamic State in Iraq and Syria (ISIS), CBC News has learned.
Canada has joined the fight against ISIS willingly, Harper said.
"We will look at whatever the requests are, we will ultimately take our own decisions based on our own capacities and the options we think are realistically available to us.
"But that said, there is no reluctance here," Harper said.
Canadians learned of a U.S. request for further military contribution in the fight against ISIS when Harper told a business audience in New York on Wednesday he had received a letter from the U.S. outlining its needs.
More to come