Conservative politicians have made several trips to Washington, D.C., over the past five years in an effort to calm fears, shore up support and offer rebuttal to critics of the project.
"We have in play here a very large project that will make a difference economically to Canada and will generate significant revenue to governments," Oliver said Wednesday after speaking at Google's ThinkEnergy Summit in Calgary.
"What is in play is greatly in excess of whatever time and costs we've incurred to advocate for it."
Oliver said until a final decision on Keystone XL is announced, it's important to maintain a presence south of the border. He was in New York earlier this week meeting with financiers and bankers.
"I think the basic facts are out. The advantages are clear. I think the environmental issues have in fact been addressed but the decision still hasn't been made," Oliver said. "It's an important project, I believe, for both countries and so we intend to continue to communicate the issues to the American public and to decision-makers."
The $7 billion pipeline would carry millions of barrels a week of Alberta oilsands bitumen and crude extracted from North Dakota's Bakken shale, to Gulf Coast refineries.
The pipeline has become a flashpoint in the U.S. debate over climate change. Republicans and business and labour groups have urged President Barack Obama to approve the pipeline as a source of much-needed jobs and a step toward North American energy independence.
Environmental groups have been pressuring the Obama administration to reject the pipeline, saying it would carry "dirty oil" that contributes to global warming. They also worry about a spill and have mounted an aggressive campaign critical of Keystone.
In his speech at the Google conference, Oliver pointed out that greenhouse gas emissions are lower per capita in Canada than in the United States. He said he doesn't mind a debate over Canada's resource and environmental record, but only if it is done fairly.
"There is a problem when some opponents use scare tactics, misinformation and wildly distorted messaging to advance their cause and that is precisely the current situation," he said.
"Opponents are targeting the oilsands as a symbol of their larger battle. Incidentally, they are opposed to all resource development ... as a result we are engaged in a decisive battle for the economic well-being of the country."
The U.S. State Department said earlier this month that it won't release its final environmental assessment of the project until it's examined and published more than a million public comments on its draft ecological analysis.
Oliver isn't the only politician who has spent a lot of time south of the border on the Keystone file.
Alberta Premier Alison Redford has visited Washington four times since becoming premier two years ago, meeting with senators and members of Congress and telling them it is essential to keep Alberta's message front and centre.
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