The White House said it was working to shield the debate over the Keystone XL oil pipeline from partisan debates and focus instead in the project's merits.

Pipeline planner TransCanada asked the U.S. State Department, charged with vetting the project, to pause a review process while the route for the pipeline is under review in Nebraska. The pipeline has become a scapegoat for political debates over North American energy policy, with supporters touting its potential to stimulate the economy and detractors questioning the continued emphasis on crude oil in an age when climate concerns are mounting.

The U.S. Congress has tried several legislative efforts to force President Barak Obama's hand on the pipeline, moves the administration said would be met with a veto.

The cross-border project was announced in 2008 and, by the standards of White House spokesman Josh Earnest, the review process has taken "an extensive amount of time." That does not mean, however, the Obama administration will let politics undermine the federal vetting procedure.

"My experience when things that are worthy of technical consideration get politicized, that rarely speeds up the technical consideration," he told reporters. "That typically has the effect of slowing it down."

An $8 billion project, pipeline planners say Keystone XL would carry some crude oil from North Dakota, along with Canadian oil, to U.S. refineries and push foreign reserves out of the North American market. It has the potential to create more than 40,000 jobs, the company said, though opponents say many of the possible benefits are overstated.

North Dakota Sen. John Hoeven, a Republican helping with the legislative push to approve the pipeline, said Keystone XL is part of a larger debate about the direction of North American energy policies.

"We must learn the lesson of history and avoid the pitfall of returning to our reliance on OPEC and the Middle East for oil," he said.

The White House said a decision on the project is expected before Obama leaves office. Earnest said the debate has been "heavily influenced by politics," though the president was trying to "shield the actual process that will consider the merits of the project from those politics."