President Obama has vetoed the Keystone XL Pipeline Approval Act, which Congressional Republicans had sent to the White House earlier today. The measure would have funded the construction of the controversial pipeline designed to transport heavy crude oil from Hardisty, Alberta, to refineries in Port Arthur, Texas.

Only the third veto issued by Obama, the action was taken quietly by way of a message sent to the U.S. Senate.

"Through this bill,” Obama wrote, “the United States Congress attempts to circumvent longstanding and proven processes for determining whether or not building and operating a cross-border pipeline serves the national interest... because this act of Congress conflicts with established executive branch procedures and cuts short thorough consideration of issues that could bear on our national interest – including our security, safety, and environment – it has earned my veto.”

However, White House Press Secretary Josh Earnest said earlier today that he “did not rule out Obama eventually approving the pipeline,” according to The Washington Post. Earnest amplified that remark by saying that the Dept. of State is “still conducting a review of whether the massive pipeline… would serve the national interest.”