OTTAWA (AFP) - US President Barack Obama is to outline a "comprehensive strategy" for Afghanistan he hopes Canadians can support, when he meets Canada's Prime Minister Stephen Harper this week, he told public broadcaster CBC Tuesday. "I am absolutely convinced that you cannot solve the problem of Afghanistan, the Taliban, the spread of extremism in that region solely through military means," he said ahead of his trip to Ottawa on Thursday. "We're going to have to use diplomacy, we're going to have to use development, and my hope is that in conversations that I have with Prime Minister Harper that he and I end up seeing the importance of a comprehensive strategy and one that ultimately the people of Canada can support," he said. A US "strategic review" of the Afghanistan mission is underway and how best to approach "the military side of the equation" would be released soon, he added. "There are a lot of concerns about a conflict that has lasted quite a long time now and actually appears to be deteriorating at this point," Obama said.