The American Petroleum Institute said the White House is showing a lack of leadership by not pushing the Keystone XL oil pipeline forward.

The U.S. State Department last week said a decision on whether or not to issue a federal permit to pipeline planner TransCanada to build the cross-border section of Keystone XL was on hold because of route issues in Nebraska.

A Nebraska court is reviewing the legitimacy of a law that gave Gov. Dave Heineman authority over the pipeline in the state. On Monday, White House spokesman Jay Carney said the process "can't continue until the situation in Nebraska is resolved."

Cindy Schild, a senior manager for downstream operations at API, an energy industry lobby group, said its polling showed most people were in support of the pipeline. President Obama, she said, was bowing to pressure from "shrill extremists" instead of the workers who would benefit from the pipeline's construction.

"The president's lack of political leadership is hurting middle class Americans," she said in a statement Thursday.

Opponents of Keystone XL worry the more viscous form of Canadian crude oil designated for the project poses a grave threat to the environment. An early 2014 report from the State Department found that threat would exist with or without the pipeline.