Hillary Clinton, the former U.S. secretary of state, says military action is "critical" to the U.S.-led fight against Islamic State militants in Iraq and Syria, but is "not sufficient" on its own.

"I think military action is critical. In fact, I would say essential to try to prevent their further advance and their holding of more territory," Clinton told an audience at the Canada 2020 conference in Ottawa.

"Military action alone is not sufficient," Clinton quickly added, describing the fight against Islamic jihadists as "a long-term commitment."

​Clinton's remarks came during a question and answer session moderated by Victor Dodig, chief executive of the Canadian Imperial Bank of Commerce.​

"We have to fight an information war as well as an air war."

She said it was "a very attractive cause for alienated young people" — in the U.S., Canada and elsewhere — who have taken up arms alongside the violent extremists.

"We turn away from it at our peril," she cautioned.

Clinton said she was aware of the debate politicians were having in Parliament, just a couple blocks away, over Canada's additional contribution to the U.S.-led mission.

"The United States, I'm sure, will welcome and respect whatever level of support Canada decides is appropriate to help meet this shared challenge."

Clinton described Canada as "an exceptional partner" in the U.S. effort toward global peace and prosperity.

"As two close friends, we will not always agree on every issue, but the core values that unite us are unshakable."

She acknowledged Canada's contribution to the war in Afghanistan, as well as the fight against SARS and most recently the outbreak of Ebola in parts of West Africa.

Clinton, widely seen as a potential Democratic front-runner in the 2016 U.S. presidential campaign, has yet to say whether she will seek the U.S. party's nomination.

Asked about her intention to run for president, Clinton said she was "thinking hard" about it but would continue to "dodge" the question.

"I'm going to keep dodging it, certainly until the mid-term elections are over."

Several hundred were in attendance to hear her speak, including several MPs and Liberal Leader Justin Trudeau.

Canada's MPs are debating a government motion to join the U.S. and its allied partners for a period of up to six months in launching airstrikes against ISIS.

The Opposition New Democrats and the Liberals are opposed to the mission.