Canadian Prime Minister Stephen Harper has told President Bush that Ottawa will withdraw its mission from Afghanistan next year unless Nato sends in more troops.
Canada, which has 2,500 soldiers in the southern city of Kandahar, is fed up with the refusal of other Nato nations to send more forces to the violent region of Afghanistan. The Canadian combat mission there is due to end in February 2009.
On Monday, Prime Minister Harper said he accepted the recommendations of an independent panel that urged Canada to end the mission unless Nato provided 1,000 extra soldiers and Ottawa obtained helicopters and aerial reconnaissance vehicles.
A White House spokesman said Mr Bush pointed out that the United States had already agreed to sent more soldiers to Afghanistan.
However, it is not clear whether the additional US troops would meet Canada's condition for more soldiers in Kandahar.
Nato says it agrees with Canada about the need to bolster its peace operation, but the alliance dismisses the idea that members are dragging their feet.