"That's the position we've given to our allies and our military men and women are very committed to that," Harper said.

He was in Halifax, Nova Scotia, to announce new funding for the Canadian Navy, the Canadian Broadcasting Corp. reported.

The government will not back down from its mission in Afghanistan, Harper told reporters and members of the Canadian Atlantic fleet.

The announcement came one day after six Canadian troops were killed by a roadside bomb southwest of Kandahar, Afghanistan.

Harper offered his condolences to the soldiers' families.

"I'm aware also of the pride (families) feel for their loved ones and the ultimate sacrifice they made for their country," he said.

Opposition leaders called for a Canadian troop withdrawal after the six soldiers were killed Wednesday -- one of the deadliest days for Canada's mission in Afghanistan -- the CBC said.