QUEBEC — Liberal Leader Michael Ignatieff says Canada should not prolong its military mission in Afghanistan even if U.S. President Barack Obama wants it to do so.

Ignatieff says he intends to press that point to Obama when he meets him in Ottawa on Thursday.

There have been indications Obama will ask Prime Minister Stephen Harper to maintain the Canadian military presence in the wartorn country.

Ignatieff, who was in Quebec City on Tuesday to meet with Mayor Regis Labeaume, said there must be a revision in the strategy in Afghanistan where Taliban and other insurgents have battled NATO forces for six years.

Ignatieff also plans to warn Obama against economic protectionism and extol the virtues of free trade.

He did praise Obama's decision to close the controversial U.S. military detention centre at Guantanamo Bay and said Canadian detainee Omar Khadr should be returned home to face justice.

"We think Guantanamo Bay did enormous harm to the reputation of the United States and we want to help Mr. Obama in any way we can to bring the Guantanamo Bay episode to a close," he said. "That necessarily means that Mr. Khadr, a Canadian citizen, should come home and face justice in Canada."

Asked if he was going to pressure Obama to return Khadr, Ignatieff said, "I don't think you ever put pressure on the president of the United States. He is our guest, we will welcome him with friendship and affection and we will have a frank and clear discussion."

When pressed, Ignatieff said he is in politics to defend the national interests of Canada.

"I never hesitate to do so, firmly and clearly."