The resolution would call on the Obama administration to move quickly to grant the necessary permits to build the line, which would pump crude from Canadian oil-sands fields to refineries in the Houston area.
The permit needed to build the line, which would run down the length of the Great Plains, is under review by the U.S. Department of State. Environmentalists say the risk of leaks coupled with increased greenhouse gas emissions from oil sands was too great. Supporters, however, contend the pipeline would create jobs and help keep a lid on gasoline prices.
"We have studied this project for long enough," Sen. Mary Landrieu, D-La., said in a written statement. "We know its tremendous economic benefits and the critical role it will have for our nation's energy security."
Landrieu and the resolution's co-sponsor, Sen. John Hoeven, R-N.D., said the issue had been under scrutiny in Washington for five years. "We need to push on all fronts to get it approved as soon as possible for the good of the nation," said Hoeven.
Although the resolution would be non-binding if approved by Congress, the vote on the floor would put lawmakers on record as being for or against Keystone.
The Hill said a similar statement was included as an amendment on the Senate Democrats' non-binding budget plan in March. That amendment was backed by 62 senators, although some said afterward their vote should not be seen as an endorsement of the project.