TORONTO — Former U.S. presidents Bill Clinton and George W. Bush both pleaded ignorance at a Toronto event over their country's new rule that will require Canadians and Americans to have passports to cross the border starting Monday.

The Friday afternoon event, which put Clinton and Bush on stage together for the first time, was "billed" as a conversation and the pair touched on Afghanistan, same-sex marriage and several other hot topic issues.

But when moderator Frank McKenna, the former Canadian ambassador to the U.S., launched into a passionate speech about how Canadians feel about the new passport rules, Bush and Clinton both seemed perplexed.

"Hell of a speech," Bush joked, before saying. "I'll be frank with you Frank, I don't know about the passport issue."

"I thought we were making good progress on using a driver's licence to cross the border. What happened to the easy-pass card?"

"I think we should be facilitating driving."

Clinton also demurred, saying he only heard of the subject a day before. He said most Americans probably didn't know about the issue.

This could mean fewer Americans coming into Canada, as less than half of Americans have passports, and could be harmful to Canada's economy, he said.

"I promise you, you have got my attention with this, so I'm going back home (and) I'll see if there is anything else I can do," he added.

Former rivals play nice

Clinton said that those in attendance at a debate between himself and his successor were "hoping for a 21st century version of the Roman Coliseum where we attempt to devour each other."

But instead, the pair of former presidents played like a pair of kittens.

For the 6,000 or so in attendance in the Metro Toronto Convention Centre, there were remarkably little fireworks from a pair that seem to be polar opposites, both politically and personally.

The pair, seemingly free from the political responsibility to be rivals, complimented each other often, and even consoled the other on tough decisions they made while in office.

Bush even went so far as to refer to Clinton as "his brother" during his opening remarks. He explained that because Clinton has become so close to his father, ex-president George H.W. Bush, in their humanitarian work, his mother refers to Clinton as "her son."

But during the 60-minute debate there was one notable exception of contention.

Speaking about U.S. President Barack Obama, Bush said "Anything I say is not to be critical of my successor."

"I didn't appreciate it when my predecessor criticized me (in public,)" he added, which drew an annoyed look from Clinton.

Clinton responded: "I tried to do it in a very respectful way."

Clinton added that because his wife, Secretary of State Hillary Clinton, was a Senator during Bush's presidency, there was additional pressure for him to be political.

While it was a mostly-Toronto crowd, and thus, Clinton received the bigger cheers of the afternoon from a liberal city, Bush was greeted very warmly and was cheered after a number of statements.

Both men pandered to their Canadian hosts. Clinton said "America has never had a better ally" and thanked Canada for its contribution in Afghanistan.

Bush spoke about the importance of free-trade between the U.S. and Canada, which drew one of the loudest cheers of the event.

However, outside was a different story, as hundreds of protesters gathered outside to denounce the presidents as "war criminals."

"Jail George Bush," some chanted, while others cheered "George Bush out, war resisters in."

A number of demonstrators also had signs calling for the release of Canadian Omar Khadr from Guantanamo Bay.

Bush on retirement

Unlike his vice-president, Dick Cheney, Bush has maintained a low profile since leaving the White House in January.

In his opening remarks, he seemed relaxed and joked about adjusting to post-presidential life.

"(Dishes) are my new domestic policy," he said his wife, Laura Bush, tells him.

Bush also told an amusing anecdote about his first walk around his new neighbourhood in Dallas with his dog, Barney.

Needless to say the story ended with the former leader of the free world, holding a plastic bag of his hand, picking up his dog's dirty business.

Regardless, "I like being in Texas. I don't miss the spotlight," he said. "Retirement is not that bad."

The controversial president, who invaded Iraq and presided over the U.S. economic meltdown, said he is writing a book that will challenge some of the beliefs about his decisions.

"History can change pretty quickly," he said. He has often contended that his decisions, particularly the invasion of Iraq, will be seen differently in the future.

While he did not outline any plans, Bush said he does "want to stay engaged with the world."

Clinton, an old pro on the speaking circuit, did not disappoint, starting out like a stand-up comedian with rapid-fire jokes, before ending on a rousing sermon on the importance of civil service.

He spoke at-length about his post-presidency humanitarian work, and almost sounded like his vice-president, Al Gore, when he made a passionate appeal on the environment.

"Global warming is going to be calamitous," he warned.

"You can do something about it. You don't need to be an ex-president of millionaire," he appealed. "You can do something about it."