"This measure is structured as a joint resolution, putting both the House and the Senate on record that the Keystone XL pipeline project is in the national interest," Hoeven said in a statement.
The amendment was inserted into the so-called Shaheen-Portman energy measure, offered by Sens. Rob Portman, R-Ohio, and Jeanne Shaheen, D-N.H. It calls for a broad-range of energy-efficiency measures.
Hoeven said Keystone XL, which would bring Canadian tar sands oil to refineries on the Gulf of Mexico, would shield North American energy markets from overseas turmoil and "ensure true North American energy independence."
President Obama said he'd weigh the project against its environmental footprint. The heavier type of crude oil designated for the pipeline is seen by critics as more corrosive to pipelines and more carbon intensive than other grades.
Anthony Swift, an attorney for the Natural Resources Defense Council, said a provision for Keystone XL has no place in an energy-efficiency bill.
"Senators should reject this measure," he said Thursday. "The proposed tar sands pipeline would increase carbon pollution and make climate change worse."
Online news service Politico reported Senate Majority Leader Harry Reid, D-Nev., threatened to pull the Shaheen-Portman bill off the floor because of disputes over Obama's healthcare requirements.