Canadian pipeline company TransCanada wants to build the Keystone XL oil pipeline from tar sands projects in Alberta to refineries along the southern U.S. coast.
Nebraska leaders last year wanted the pipeline rerouted around an aquifer, prompting another federal review of the project.
Last year, Republican leaders gave U.S. President Barack Obama until mid-February to decide on Keystone XL and he rejected TransCanada's permit because of the "arbitrary" deadline. TransCanada can reapply.
A bill drafted by U.S. Sens. John Hoeven, R-N.D., Richard Lugar, R-Ind., David Vitter, R-La., and more than 40 other senators, including one Democrat, gives TransCanada the approval to move ahead while Nebraska reviews an alternative route.
"Our legislation not only acknowledges the vital national interest this project represents on many levels but also works in a bipartisan way to begin construction," Hoeven said in a statement.
Project supporters say Keystone XL will enhance U.S. energy security while adding jobs to a weak American economy. Critics question those claims. Senate Majority Leader Harry Reid, D-Nev., last week claimed much of the crude oil sent through Keystone XL would likely be shipped overseas.