The State Department says it needs more time to make a decision about whether to approve the Keystone XL pipeline project, citing uncertainty about the route's direction through Nebraska, which is currently under litigation there.

The department is delaying the deadline for eight federal agencies to submit their recommendations to on the pipeline, which President Obama had requested they do via an executive order. The original deadline was early May, but because Nebraska's Supreme Court is hearing a case on the proposed Keystone route through that state, the agencies will have about two weeks after the case is closed to submit their recommendations.

The process ahead, including whether the State Department will have to redo its initial assessments on the project, now depends on the outcome of the Nebraska case - the conclusion of which a senior State Department official declined to speculate about Friday.

"I can't render a judgment on when the final decision could take place. We want this to move as expeditiously as possible," the official told reporters on a conference call.

The officials also noted that there had been an unprecedented 2.5 million public comments regarding the pipeline, which State Department staff and private contractors are still going through. Usually, the official said on the call, there are less than 100 public comments on pipeline projects.

But this pipeline has become a particularly hot-button political issue, with supporters of the project criticizing the Obama administration for dragging its feet on approval, and bipartisan sniping began almost instantly after the announcement went public.

"It is crystal clear that the Obama administration is simply not serious about American energy and American jobs. I guess he wasn't serious about having a pen and a phone, either," Senate Republican leader Mitch McConnell said in a statement, minutes after the State Department announced its decision.

Sen. Mary Landrieu, D-La., who is facing a tough re-election battle this year, also reacted quickly: "Today's decision by the Administration amounts to nothing short of an indefinite delay of the Keystone Pipeline. This decision is irresponsible, unnecessary and unacceptable."

"The administration is sending a signal that the small minority who oppose the pipeline can tie up the process in court forever," she said.

The pipeline route runs from Alberta, Canada, to refineries in Steele City, Neb.; Wood River and Patoka, Ill.; and the Gulf Coast of Texas. When fully completed it will stretch over 2,000 miles.