Montreal  - As Canadians eagerly anticipate President Barack Obama's first foreign visit in Ottawa Thursday, many are also worried by hints at growing US trade protectionism and possible US pressure on Canada's commitment to Afghanistan.

Not since President John F Kennedy's 1961 visit has there been so much enthusiasm for an American president. Obama's 82-per-cent Canadian popularity rating is even more than the combined total of Prime Minister Stephen Harper (35 per cent) and the official opposition leader Michael Igantieff (44 per cent.)

Tens of thousands of people are expected to line Ottawa streets to catch a glimpse of Obama.

But beneath this enthusiasm and renewed good will lies growing unease about Obama's economic policies, which could threaten free- flowing bilateral trade worth 1.5 billion dollars a day.

The "buy American" provision in the 787-billion-dollar US economic stimulus package is seen as a harbinger of a growing protectionist mood in its requirement for public works projects to use US iron, steel and manufactured goods.

Canada, which sold 7.6 billion dollars worth of steel and iron products to the US in 2007, lobbied hard against the provision.

Obama addressed the issue in an interview with the Canadian Broadcasting Corp. (CBC) Tuesday, saying he was committed to strengthening the US economy in a way that will enhance "the ability of trading partners like Canada to work within our boundaries."

"I think that if you look at history one of the most important things during a worldwide recession ... is that each country does not resort to 'beggar thy neighbour' policies, protectionist policies. They can end up further contracting world trade," Obama said.

The fate of the Canadian auto industry could also come up in the Harper-Obama talks. Canada's federal government has offered its own 3.3-billion- dollar bailout package to Detroit's Big Three - General Motors, Ford and Chrysler, in addition to Washington's 17.4 billion dollars pledged to Chrysler and GM. Ontario projects it would lose
600,000 jobs if the Detroit automakers left Canada or otherwise collapsed.

There is also unease that Obama might pressure Canada to stay in Afghanistan beyond its pullout date of 2011. Canada has about 2,700 soldiers in Kandahar, the most volatile province of Afghanistan. With 108 dead and over 300 wounded, Canada has lost per capita more than any other NATO country in Afghanistan.

Speaking to reporters during a phone briefing from Washington Tuesday, Dennis McDonough, a top Obama foreign policy adviser, said the US president would like to thank Canada for its efforts but would also seek a continued multinational effort in solving international problems such as Afghanistan.

"It is vitally important that America revitalize its alliance," McDonough said, "and to use those alliances to advance our shared goals and our shared interests, be that on global challenges like Afghanistan or democracy throughout the hemisphere, or concrete and aggressive efforts to stem global climate change."

Potentially even more damaging for Harper's political base in Western Canada are Obama's goals of weaning the American economy off foreign energy and introducing tough carbon emission standards.

Canada is the United States' number-one energy provider, mostly from its gas fields and the tar sands in Canada's prairies. Canada accounts for about 20 per cent of US imports of crude and oil products.

But extracting oil from tar sands in Alberta and Saskatchewan requires open pit mining techniques and tremendous energy and water use, earning the oil sands the "dirty oil" nickname.

"What we know is that oil sands create a big carbon footprint," Obama said in the CBC interview. He added that ways had to be found "to grow our economies in a way that is not rapidly accelerating climate change."

It's not clear if another issue - Guantanamo prisoners - will be on the table during Obama's six-hour stay,

Canadian civil and church groups are hoping it will be. Canada is the only Western country that still has one of its nationals in Guantanamo, Omar Khadr, who was 15 when he was arrested in Afghanistan for killing a US special forces medic in 2002. Human rights groups have been pressuring the Harper government to seek Khadr's repatriation.

Canadian church groups have applied to Canada's federal government to sponsor five Guantanamo detainees as refugees, including a Syrian Kurd, an Algerian and three Uighurs, members of a Turkic Muslim group in northwestern China. There is scant evidence against them, but the US is reluctant to return them to their native countries for fear they could face arrest and torture.

In a separate bid, Amnesty International and the Canadian Council for Refugees are pressing the Harper government to accept all 17 Uighur detainees. Beijing has declared them terrorists and demanded their extradition to China. (dpa)