Former U.S. secretary of state Hillary Clinton said Canada is the United States’ “indispensable partner” on the world stage in a lunchtime speech to a Toronto business audience Monday.

Clinton’s speech to the Toronto Region Board of Trade at the Sheraton hotel in downtown Toronto was part of her promotional tour for her latest memoir, “Hard Choices,” which was released last week.

The former First Lady, senator and Secretary of State opened her talk by praising the unique relationship between the United States and Canada, calling it “an effective model” for countries around the world.

“Canada is our indispensable partner in nearly everything we do around the world,” Clinton said. “No two countries are closer than we are.”

But in a question-and-answer session with former New Brunswick premier Frank McKenna afterward, she acknowledged that the debate over the proposed Keystone XL pipeline has strained the relationship.

Both opponents and advocates of the project are “making arguments in good faith,” she said, adding that “it’s a very deep disagreement.” But she warned against allowing that disagreement to become a “proxy for the (Canada-U.S.) relationship.”

“It is one pipeline,” she said, adding that the two countries should be working together to create a joint approach to energy and climate change issues.

“The (Keystone) decision should be put in a broader context,” Clinton said. “Because I do believe that both Canada and the United States can be richer and more prosperous and more environmentally sustainable by a broader engagement.”

Clinton’s book tour coincides with the growing speculation south of the border about who will run for the Democratic and Republican nominations for president ahead of the 2016 election.

Clinton has yet to formally declare whether she will once again seek the Democratic nomination for president after losing to Barack Obama in 2008.

But she is considered a front-runner for the nomination.

McKenna left those questions to the end of the event, first asking what the husband of a female president would be called.

“Speaking hypothetically,” she joked, before naming some of the suggestions that she has heard, including First Man and First Mate.

“I hope someday our country has an opportunity to figure that out,” she said.

Asked more directly about whether she was prepared to not only shatter the glass ceiling of the White House but break right through the front door, she joked: “Gosh Frank, I don’t think we should be talking about coups.

“I’ve been in and out of there a lot. I’m not sure that kicking down the front door is an appropriate metaphor for the changes that we need to make.”

She went on to lament the current political climate in the U.S., where “people are talking about issues without listening to each other,” and failing to compromise.

“We need to summon a unity of purpose in our country again,” she said. “However that’s done, I think it’s going to take some time to try to get into the right balance once more between our high regard for individualism and our deep yearning for community, and how we once again embed that in our national politics.”

Whatever she chooses to do in the future, she said, she “will continue to work for that.”

Hilary Clinton sits down with Canada AM in an interview broadcast Tuesday, June 17 on CanadaAM.CTVNews.ca, CTV News GO, CTV News Channel and CTV.