VANCOUVER, British Columbia (Reuters) - Canada's Afghanistan mission has cost much more than publicly stated, a government report estimated on Thursday, but Prime Minister Stephen Harper pledged troops will stay until 2011 no matter who wins next week's Canadian election.
The mission, which has killed nearly 100 Canadian soldiers, has already cost up to C$10.5 billion ($9.1 billion) and the price could hit C$18 billion if troops stay in Afghanistan as long as now planned, the Office of the Parliamentary Budget Officer estimated.
Canada has 2,500 troops in Afghanistan in a combat mission in the violent Kandahar region.
The Conservative government has publicly estimated the war's cost so far at C$8 billion, but Parliamentary Budget Officer Kevin Page said he does not know how that figure was calculated and that Canadians have never received a detailed picture of what they are paying.
The report by the independent budget office comes as Canadians prepare to cast ballots in a general election on October 14. The war, while controversial in Canada, has been largely eclipsed as a campaign issue by debate over the economy and environmental taxes.
Harper said Canada would spend as much as needed to keep its military and aid efforts in Afghanistan safe, and said both his Conservatives and the main opposition Liberals have pledged to meet the country's commitment to stay there into 2011.
"We are doing important work there, it's part of an international effort... it's a commitment we took when we invaded that country," Harper told a campaign news conference in British Columbia. "We're not hiding the fact that these things are expensive."
Page said the C$18 billion figure was only "incremental costs" so it did not include money the military would have spent even if it was not in Afghanistan.
The government's C$8 billion figure is believed to include money that the military would have normally spent during that time, he told an Ottawa news conference.
"If we were to provide an estimate on a full cost basis it would be a much larger number," Page said.
The opposition New Democratic Party, which has called for Canada to withdraw its troops, said the report was more evidence that the mission had failed.
"If the mission is not working now, then why are we continuing with three more years of the same?" asked Paul Dewar, the NDP member of Parliament who requested the budget office prepare the report.
Finance Minister Jim Flaherty said the war effort was adequately budgeted for. "I'm satisfied that we have a good handle on the actual costs," he said.
Reporting Allan Dowd, Randall Palmer, Editing by Peter Galloway