"I do believe that the building of Keystone makes sense," he added, "if the environmental issues and the sighting issues can be resolved in a fashion that protects the environment and is done in a fashion that provides … time for consideration.
"If it can be done right, yes, I'm for Keystone," Hoyer said.
In January, administration officials rejected TransCanada Corp.'s application to expand the pipeline from the oil sands of Alberta, Canada, to Gulf Coast refineries. They emphasized that their decision was not based on the merits of the proposal, arguing instead that they simply hadn't had enough time to gauge the environmental impact of the project, as required by law.
House Republicans have passed several proposals this year expediting approval of the project, most recently as part of a short-term transportation bill. That legislation is poised to go to conference with a bipartisan Senate-passed bill sans the Keystone provision.
Senate leaders in both parties this week named the lawmakers who will participate in that face-off over Keystone's fate.
Hoyer conceded there's "significant support" for the pipeline among House Democrats, noting that 69 Democrats voted in favor of the GOP's transportation bill. But he also suggested that not all of those 69 lawmakers support a quick approval of the pipeline.
"You can't overanalyze that vote, because there were just, there were a lot of people [who] just thought we ought to go to conference and get this thing done," he said. "You can't interpret that all of those votes were votes that were in favor of Keystone."