Chief of Defence Staff General Raymond Henault, in a teleconference call from Brussels where he is attending North Atlantic Treaty Organization meetings, said of the Afghanistan mission: "There is a challenge to that mission, there is no doubt."

Asked whether the mission -- dubbed Operation ATHENA -- was really "Mission Impossible," he insisted his troops were "combat capable and well-trained for peacekeeping operations. It is not Mission Impossible.

"I think it is a mission we can do and we can do well."

Canada is due to send 1,800 troops to Afghanistan in August for a six-month tour to replace the first contingent with another 1,800 troops for another six-month tour.

But he recognized that continuing peacekeeping missions around the world, especially in the Balkans, had "taken a toll on our men and women, quite frankly."

And he admitted that Canadian Forces would be "stretched" if they had to take on any additional international missions in the next 18 months.

Henault also threw his weight behind the controversial US missile defense plan. Ottawa said in May it would start talks with US officials over the plan.

"Missile defence is important for us to be involved in," he said, refusing to be pulled into the controversy over whether such a plan should allow weapons to be put in space.

WAR.WIRE