Prentice says he remains cautiously optimistic about the pipeline's future as the House of Representatives prepares to vote on the project Friday.
If approved, a bill on TransCanada Corp.'s (TSX:TRP) Keystone proposal would move to the Senate and then to U.S. President Barack Obama.
The US$8-billion line would take bitumen from Alberta diagonally across the continent to refineries and ports in Texas.
Prentice has said getting Alberta oil to coastal ports is crucial to growing the provincial and Canadian economies.
The line has been tied up in the approval process for six years and has faced stiff opposition from environmentalists.