MONTREAL - Canada is trying to offset the negative perceptions of the oilsands by appealing to American concerns about high unemployment, the Canadian ambassador to the United States said Thursday.

Former Manitoba premier Gary Doer said few Americans know Canada outstrips Saudi Arabia as its largest oil supplier.

"We're trying to work on their high unemployment rate, their oil security and job opportunities as an argument," he said during a speech to the Quebec Manufacturers and Exporters Association.

There are 900 companies in the United States that supply Canada's western oilsands, including trucking giants like Caterpillar, he said.

Doer said he's constantly reminding Americans and their political leaders that Canada is its largest and closest trading partner, buying more U.S. products than the European Union.

"They don't know we sell the most oil to them...have the most tourists and so part of your job (as ambassador) is to repeat over and over and over again that we are your biggest customer and treat us like your biggest customer."

A proposed $7-billion Keystone XL pipeline proposed by Calgary-based TransCanada Corp. (TSX:TRP) could reduce American dependency on oil from the Middle East and other regions, concluded a report commissioned by the U.S. government.

The proposed 3,060-kilometre pipeline would carry more than 500,000 barrels a day of crude oil derived from the tarry substance known as bitumen.

The report found that Keystone XL will also create 20,000 high-paying jobs for American families and inject $20 billion into the U.S. economy.

Environmental groups call the call the pipeline an ecological disaster waiting to happen and say the so-called oilsands produce "dirty" oil that requires huge amounts of energy to extract.

The Canadian ambassador's sales efforts are made more challenging by protectionist efforts such as the 2009 Buy America law designed to protect U.S. jobs.

"If you have a high unemployment rate like they have in the United States, you're more susceptible to arguments on Buy America or protectionist policies."

But Doer noted that recent television ads on trade run by political parties targeted China, not Canada.

A recent Pew Research poll found that Americans viewed Canada as its most respected trading partner.

Notwithstanding the political rhetoric, American politicians know they can't get beyond a nine per cent unemployment rate without increasing trade, Doer added.

"I feel right now there is the mood for working on trade agreements in a positive way," he said.

That approach could materialize in three years when the softwood lumber agreement that imposed duties on Canadian suppliers is scheduled to end.

Canadian producers have offset lower exports south of the border by increasing sales abroad, including to emerging countries in Asia.

While Americans will remain a big purchaser of Canadian lumber, the United States could feel the consequences of its trade approach when the new housing market improves in a few year, Doer told reporters.

"You could see a situation in three years where there's a shortage of wood because of some narrow disputes that we've had."

Despite the ongoing efforts to remove trade irritants between the two countries, Doer said the biggest issue they face is security -- both domestically and internationally.