Democrats stopped the bill from passing through the chamber by a vote of 59 to 41. Sixty votes were needed to invoke cloture.
However, Prentice said that he is looking towards the new Senate that will be sworn-in January.
“I’m certain that the process will carry on at that point in a Senate that’s more clearly dominated by Republicans,” Prentice said in Edmonton shortly after the vote on Tuesday.
Prentice sees today’s vote as a step along the way and not the end of the process.
“I continue to be optimistic as this works forward," he said. "I can’t predict what will happen in the U.S. legislative process or the timing but I think there’s never been more bipartisan support, it’s never been stronger and I find that very encouraging.”
Prentice said approval of the Keystone project is in the best interests of Canada and the United States. Prentice plans to head to Washington in January to meet with legislators. No dates have yet been set.