Relying on Canadian crude imports is the best choice for the United States – not just because it's reliable and secure but because of Canada's unmatched environmental record, Natural Resources Minister Joe Oliver said Tuesday.

Adding green to the attributes of Alberta's oil sands is the latest twist in Ottawa's concerted effort to push for U.S. approval of the controversial Keystone XL pipeline designed to funnel more than 800,000 barrels a day of Canadian crude to Texas Gulf oil refineries next to deep-water export terminals.

"The oil sands are a greener alternative than some other sources from around the world," the minister said in news conference from Chicago after delivering a speech touting Keystone merit's to the Chicago Council on Global Affairs.

Story continues below advertisement

But Mr. Oliver conceded he was "not sure about the label," referring to the use of the term "green" in connection with the carbon-laden crude from Alberta's vast oil sands.

Rather it was Canada's overall performance on reducing greenhouse gas emissions and the Harper government's commitment to future reductions that add a greenish tinge to Canadian energy exports when compared to alternatives.

The minister also accused opponents of the Keystone XL pipeline of vilifying the project unfairly.

"Many opponents are spreading false information about the oil sands, especially its impact on the environment," he said in his speech.

Mr. Oliver's latest trip to the United States is part of a campaign of visiting Canadian premiers and ministers extolling Canadian energy exports in general and – in particular – the Keystone XL pipeline. As President Barack Obama mulls whether to give Keystone a green light or block it as part of a new-found commitment to action on climate change, the Canadian lobbying effort is intended to add "green" to reliable and secure as an attribute of the oil sands.

"I'm here to give you the unvarnished goods – and to let you make up your own mind about the merits of Canadian oil for America," Mr. Oliver said. On Wednesday he will take his pro-Keystone message to a refinery in Texas and then an industry conference in Houston.

"Canada is the environmentally responsible choice for the U.S. to meet its energy needs in oil for years to come," Mr. Oliver said.

Story continues below advertisement

In Chicago, the minister met with Rahm Emanuel, the mayor and former chief of staff to President Obama, whose easy access to the Oval Office could make him an important voice when the Keystone decision is made later this year.

After a morning visit to a union-run training centre for welders and pipefitters in Mokena, Ill., the minister told a gathering of Chicago businessmen that they could have oil and jobs and help save the planet from man-made climate change by backing Keystone.

"Canada is a global environmental leader … and yes, that includes the oil sands," Mr. Oliver said.

He called Alberta's oil sands "safe, (with only) a negligible effect on emissions" adding they "will bring significant national security benefits, jobs and revenues" to the United States while coming "from a reliable, friendly and environmentally responsible country."

Mr. Oliver painted a rosy vision of Keystone unlocking additional Canadian oil exports that "could enable a future that sees the U.S. virtually eliminate its reliance on less reliable and less environmentally responsible foreign sources."

He dismissed the strident and growing opposition to Keystone as a noisy "fuss" by climate activists trying to turn the pipeline into a symbol in a larger battle against "hydrocarbons and specifically the oil sands."