API Executive Vice President Marty Durbin expressed support for bipartisan legislation introduced last week meant to facilitate the approval of Keystone XL, a pipeline planned from Canada to southern U.S. refineries.
Durbin said state and federal reviews of the pipeline have found few direct threats to the environment.
"After four comprehensive federal reviews and a Nebraska review, the science continues to say that Keystone XL will have no significant impact on the environment," he said in a statement. "It's time to put the pipe in the ground."
House Republican supporters of the project have sought to strip President Barack Obama of authority to approve the project. It needs federal approval as a cross-border pipeline.
The pipeline would carry so-called tar sands oil, a type of crude oil seen as more carbon intensive and more of an environmental threat than conventional crude oil.
The U.S. State Department's recent assessment of the pipeline found environmental effects of tar sands production would continue with or without the pipeline.
Bold Nebraska, a group opposed to Keystone XL, says most of the benefits touted by its supporters are inflated.