CFB PETAWAWA, Ont. - Canada's mission in Afghanistan is set to undergo a "dramatic" transformation in the coming year as American troops flood into the country, a senior Canadian diplomat said Thursday.

The influx will have a "remarkable and positive impact" on what Canada is trying to achieve in the war-torn country, said Ben Rowswell, deputy head of Mission in Kabul.

"We are on the cusp of a significant transformation in the mission where ... the American forces are going to flow into part of Kandahar and into Helmand province," Rowswell said.

"That will have a dramatic effect on the insurgency capacity to move across the border easily and will have a complementary effect, therefore, on our own operations."

U.S. President Barack Obama has ordered thousands of American soldiers to deploy to Afghanistan as Washington moves to end its involvement in Iraq.

Many of the soldiers will be used in the volatile Kandahar area of southern Afghanistan, where Canadian forces have battled a determined insurgency at heavy cost.

Rowswell's comments came at an event at CFB Petawawa, Ont., that brought together representatives of the government, military and civilian agencies to discuss Canada's mission in Afghanistan.