U.S. President Barack Obama made a quick trip to Canada on Thursday - his first foreign journey since assuming office.  His talks with Canadian Prime Minister Stephen Harper focused on the global economic recession, trade, energy, the environment and the future of Afghanistan.

They met at a time of global turmoil and stressed their common ground.

"The economy and our security are being tested in new ways, and the prime minister and I focused on several of those challenges today," said President Obama.

The challenges include boosting the international economy while protecting the environment, and developing new strategies for dealing with Afghanistan.

At a joint news conference in Ottawa with Prime Minister Harper, President Obama spoke of trade as a way to spur global economic growth.  He sought to ease fears of American protectionism at a time of recession.

"I recognize the concerns of Canada given how significant trade with the United States is to the Canadian economy," he said. "I provided Prime Minister Harper an assurance that I want to grow trade and not contract it."

Canada is America's biggest trading partner - with about $1 billion daily in cross-border trade.

It is also the largest exporter of oil and natural gas to the United States - surpassing even Saudi Arabia.

Much of it is tar sands oil - heavy crude that is found mixed with sand and clay.  It is removed in a process that produces large amounts of greenhouse gases.

Prime Minister Harper said the United States and Canada are launching an initiative to develop new clean energy technologies to deal with tar sands oil as well as emissions from the coal used to fuel power plants in the United States.

"We are establishing a U.S-Canada clean energy dialog, which commits senior officials from both countries to collaborate on the development of clean energy science and technologies that will reduce greenhouse gases and combat climate change," he said.

The two leaders also discussed Afghanistan.  While Canada is pulling its troops out by 2011, the United States is sending more in.

President Obama said he did not urge Prime Minister Harper to rethink the position of the Canadian government.

"I certainly did not press the prime minister on any additional commitments beyond what has already been made," he said. "All I did was to complement Canada on not only the troops that are there and the 108 that have fallen as a consequence of the engagement in Afghanistan, but also the fact that Canada's largest foreign aid recipient is Afghanistan."

Mr. Obama was asked when and if the United States would send more troops to Afghanistan beyond the 17,000 reinforcements announced this week.  He said that depends on the outcome of an ongoing policy review.

"That review, which will be wide ranging will then result in a report that is presented to me," said President Obama. "And at that point, we will be able to provide you I think with some clearer direction in terms of how we intend to approach Afghanistan."

President Obama's visit to Ottawa was brief - less than seven hours.  But his reception in the snows of the Canadian capital was warm.

Canada has become the first foreign destination of choice for new U.S. presidents. The lone exception was George W. Bush.  The former Texas governor made his first trip as president to Mexico.