CALGARY - The outgoing U.S. ambassador to Canada says he expects the North American Free Trade Agreement to stay intact once the new Democratic administration takes power, despite worries earlier this year that the pact could be reopened under Barack Obama.

Obama, who is set to take office on Jan. 20, had mused about reopening NAFTA during the presidential primaries, spurring a great deal of furor north of the border.

But any talk of tearing up the trade pact during was likely just "campaign rhetoric," David Wilkins told a Calgary business audience Wednesday.

Once the Obama administration "gets all the facts and figures, it will understand that NAFTA is simply too beneficial to Canadians and Americans to try to unilaterally renegotiate our withdrawal and will continue to support it very strongly," he said.

Wilkins, a staunch supporter of President George W. Bush, was appointed ambassador to Canada in June 2005.

Addressing a luncheon hosted by Calgary Economic Development as part of his farewell tour, Wilkins touted Canada's integral role in America's energy security.

"It is Canada, not the Middle East, that is the United States' No. 1 foreign supplier of oil, natural gas and uranium," he said.

"And in our troubled world, it's a good thing to have our closest friend and ally producing and providing a major portion of our energy needs."

Wilkins acknowledges environmental concerns over the oilsands need to be addressed.

"I think it's important for Canada and for Alberta to be proactive and to get its message out and to emphasize pro-environmental steps it's taken up here," he said.

Dan Woynillowicz, with the Calgary-based environmental think-tank Pembina Institute, said there have been encouraging signs from Obama and his team regarding the environment so far, but that he's anxious to learn some specifics.

"I think a lot of people, whether it's in the environmental community or the Canadian government or the oilpatch are in somewhat of a wait-and-see mode, waiting for President Obama to assume office and see what direction he takes the United States in," he said.

There have been many vocal opponents in the United States to the importing of "dirty oil" from Alberta's oilsands, which has a much bigger carbon footprint than other sources of energy.

The state of California established a low-carbon fuel standard in 2007. A similar clause has been incorporated into the federal Energy Independence and Security Act, although there have been some efforts in Congress to quash it.

Market dynamics will play a bigger role in how much Canadian crude finds its way into the United States than legislation will, Woynillowicz said.

"The market signals that are increasingly coming from the United States, and may well increase under president-elect Obama, are the market is going to be seeking out fuels that have a lower carbon footprint than what we've got today," he said.

"The oilsands are headed in the opposite direction. It's much more carbon intensive to extract, upgrade and refine product from the oilsands."

Some people have "polarized" the issue into whether or not the U.S. government will ban crude from the oilsands, but Woynillowicz said he sees the debate as much more nuanced.

"They're going to set a bar in terms of performance on greenhouse gas pollution and if the oilsands industry is able to clear that bar by achieving some real and significant reductions in their carbon emissions, then they would still have some access to that market," he said.

"But if they fail to do so then that market may no longer be open to them."

University of Calgary economics professor Bob Schulz said he expects a lot of "sabre rattling" on the environmental front, but that in the end, not much will change under Obama.

"At the end of the day, the U.S. needs Canadian oil for national security," he said. "So I really don't see how the U.S. could ever try to push other agendas."