"I think it's important not to let whatever that decision is on one pipeline colour the potential for co-operation ... between the United States and Canada on energy production and climate change," Clinton told about 2,500 business leaders at a private event in Calgary on Thursday.
She offered little assurance to the oil and natural gas sector about approval for the proposed pipeline.
"I have nothing more to add to that or on what will happen."
The $5.4-billion pipeline would carry bitumen from the oilsands in northern Alberta to refineries along the Texas Gulf Coast. The project has been in limbo for more than five years and has become a symbol of the political debate over climate change.
"What pipeline?" Clinton joked during a question-and-answer period with former New Brunswick premier Frank McKenna following the speech.
"This is a pipeline that crosses our international border and so falls under the purview of the State Department," she said.
"During the four years I was the secretary, there was a very comprehensive process that took into account many different factors, including some of the concerns ... (such as) pipeline capacity as well as jobs. I can't comment any further than that.
"It's still an ongoing process and ultimately Secretary (John) Kerry will have to make a decision."
Kerry is leading a regulatory review of Calgary-based TransCanada Corp.'s (TSX:TRP) pipeline proposal and is accepting public comments, including a letter of support from the Canadian government.
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