President-elect Donald Trump said Tuesday that he intends to streamline the approval process for projects with $1B or more of investment in the U.S., though it is unclear if he will be able to bypass some of the country's environmental laws to do so.

“Any person or company investing ONE BILLION DOLLARS, OR MORE, in the United States of America, will receive fully expedited approvals and permits, including, but in no way limited to, all Environmental approvals,” Trump wrote in a post on Truth Social. “GET READY TO ROCK!!!”

Trump may initially be constrained by the National Environmental Policy Act, a federal environmental law that dates back to 1978 and mandates that federal agencies conduct environmental reviews prior to taking actions like approving energy production and infrastructure projects.

During Trump's first term, he made changes to the law to streamline the approval process, but President Joe Biden's administration reversed many of Trump's alterations in 2022.

Under current law, the president can ask agencies to “act with alacrity for particular high priority actions,” William Buzbee, a law professor at Georgetown University, told The Hill.

The law doesn't provide a fast track for large projects with significant investments, he told the outlet.

But the scope of NEPA could change, with the Supreme Court hearing arguments Tuesday in a case centered on the environmental act. The court is determining whether upstream and downstream impacts from a project should be considered as a part of the environmental reviews required by NEPA.

Companies and corporate lobbying groups have opposed NEPA for its lengthy review timeline, which they say adds to the cost of projects.

Environmental groups say it is key to protecting public heath and the climate.

“Corporate polluters cannot bribe their way to endangering our communities and our clean air and water,” Mahyar Sorour, director of beyond fossil fuels policy at the Sierra Club, told The Hill a statement.