In the wake of judicial decisions effectively shutting down the Atlantic and Dakota Access interstate pipeline projects, the Supreme Court of the United States has ruled that construction on the infamous Keystone XL tar sands oil pipeline cannot begin, thus rejecting a bid by President Donald Trump’s administration to jump-start the long-delayed project.

Trump, in one of the first acts of his presidency, signed an executive order for Keystone XL to proceed.

The Supreme Court maintained that the pipeline must still abide by the arduous environmental review process.

If lengthy enough, that process could jeopardize the pipeline's existence, pending the outcome of the 2020 election. Democrat Joe Biden has pledged to rescind the permit for Keystone if he wins.

TC Energy, Keystone's main sponsor, said “TC Energy remains committed to the future of this project,” the company said in a statement. “We will continue to evaluate our 2020 U.S. scope. In Canada, our work in 2020 remains unchanged.”

Keystone XL is a key project for Canadian oil-sands producers that have been hamstrung for years by a lack of pipeline capacity. The line would help carry 830,000 barrels of crude a day along a 1,900-kilometer route from the Alberta oil hub of Hardisty to Steele City, Nebraska. From there, the oil would travel to U.S. Gulf Coast refineries that are geared to process the heavy oil-sands crude.