NIAGARA-ON-THE-LAKE, Ont. - The "tough going" in Afghanistan that's claimed 71 Canadian soldiers has been compounded by the failure of the United States to send more of its soldiers into the war-torn country, but Canada must stand by the mission all the same, former U.S. president Bill Clinton said Tuesday.

In a speech aimed at convincing business leaders to find the economic benefit in tackling global warming head on, Clinton paused to make an appeal for Canada's continued "good work" in Afghanistan.

"I promised myself ... I would never come to Canada without thanking you for what I know is often unpopular, which is the participation of the Canadian Forces in Afghanistan," Clinton said.

"I know it's tough going and the United States has made it worse, in my opinion, by not sending enough forces there of our own because of our preoccupation with Iraq, but you did a good thing."

Polls suggest that many Canadians are opposed to remaining in Afghanistan until 2011 and would like to see soldiers withdraw by the initial target date of February 2009.

The Harper Conservatives have repeatedly promised that the final say on the mission will not belong to them but to Parliament -- which will be able to vote sometime in the next few months.

The government has also set up a task force, headed by Liberal John Manley, to offer advice on the mission.

Clinton concluded his words on Afghanistan with a plea for Canadian policy makers: "I hope you'll stay."

The former U.S. president worked the Afghan message into the broader speech he delivered in this picturesque southern Ontario town, one that focused on the challenges facing the global community -- including global warming -- and how to overcome them.

Despite such weighty issues, Clinton didn't let the chance pass to joke about the strength of the Canadian dollar against the U.S. greenback.

"I thought if I spent the night here I might have to take a loan," he said.

On the environment, Clinton lauded the work of his former vice president Al Gore and challenged the audience of political and business leaders to see global warming as an economic opportunity.

Oil and gas companies must refocus themselves into becoming "energy" companies that rely on biofuels, he said.

Clinton also targeted inequality, including the lack of access to health care, as a major problem facing the global economy and implored Canada to stick by its political and social institutions.

"Don't ever let the health-care tail wag the health-care dog, or else you'll be in trouble," Clinton said, adding U.S. manufacturing jobs have been lost to Canadian companies in recent years due to the country's health-care policies.

Clinton's speech opened this year's Ontario Economic Summit, an annual gathering of provincial political and business leaders.