Hoeven, a former North Dakota governor, met in Washington with Canadian Foreign Minister John Baird and Canadian Ambassador to the United States Gary Doer specifically to discuss prospects for the pipeline from Alberta province in Canada.
"We're going on six years now that the American and Canadian people have been waiting for an answer on whether the U.S. government will allow the Keystone XL pipeline to be built," the senator said in a statement Wednesday. "It is well past time for a 'yes' on this important project."
A cross-border pipeline, Keystone XL needs approval from the U.S. federal government to proceed. Pipeline company TransCanada's project would deliver Canada's heavier grade of crude oil recovered from tar sands to refineries in the southern United States.
The project is controversial because processing Canadian crude oil is seen as more carbon intensive than other grades and U.S. President Barack Obama said he'd weigh the need for the pipeline against its environmental footprint.
The pipeline could also carry crude oil from the Bakken reserve area in North Dakota, though it wouldn't pass through the state.
Notable deaths of 2014 [PHOTOS]