The U.S. Army Corps of Engineers denied Energy Transfer Partners LP a permit to build a section of the $3.8 billion Dakota Access Pipeline in North Dakota after weeks of opposition from Native Americans, environmentalists and other groups. “There’s more work to do” in exploring alternative routes, Jo-Ellen Darcy, the corps’ assistant secretary for civil works, said in a statement Sunday, rejecting the company’s request for a permit to route the line under Lake Oahe. The move punts a decision to the administration of President-elect Donald Trump. He expressed support for Dakota Access as recently as Dec. 1. Protests against the crude-oil pipeline have resulted in hundreds of arrests and drawn support from celebrities. The standoff is emblematic of a broader effort by environmentalists to stall oil and gas pipelines, which they say aren’t needed and hurt the nation’s progress in reducing its reliance on fossil fuels. Protesters camped for months in North Dakota had been told the area would be closed on Monday and they would have to move to designated protest zones. Energy Transfer Partners and Sunoco Logistics Partners LP called the move “a purely political action” in a Business Wire statement, adding that they are fully committed to bringing the project to completion. “This is nothing new from this administration, since over the last four months, the administration has demonstrated by its action and inaction that it intended to delay a decision in this matter until President Obama is out of office,” the companies said in the statement. The setback may be temporary. While the decision by President Barack Obama’s administration prevents the pipeline’s completion for now, analysts and Republican leaders have said Energy Transfer will probably receive the approval it seeks after Trump takes office in January. Trump Administration “The Obama administration’s refusal to issue an easement for the Dakota Access Pipeline violates the rule of law and fails to resolve the issue,” North Dakota Senator John Hoeven, a Republican, said in an e-mail. “Instead, it passes the decision off to the next administration, which has already indicated it will approve the easement, and in the meantime perpetuates a difficult situation for North Dakotans.” Hoeven called for the protesters to immediately vacate the site. Dakota Access has been central to the intensifying debate over the need for new pipelines in the U.S. It has become a rallying point for the anti-fossil fuel movement and has drawn intense opposition from Native Americans who say it’ll damage culturally significant sites. “We wholeheartedly support the decision of the administration,” Dave Archambault II, tribal chairman of the Standing Rock Sioux Tribe, said in a statement on Sunday. “In a system that has continuously been stacked against us from every angle, it took tremendous courage.” The pipeline could help cut costs for drillers in North Dakota’s Bakken shale region that have turned to more costly rail shipments when existing pipes filled up. Dakota Access, with a capacity of about 470,000 barrels a day, would ship about half of the current Bakken crude production and enable producers to access Midwest and Gulf Coast markets. The permit would be for the final section of the pipeline, which spans four states. The project was originally slated to be operational at the end of this year. “The thoughtful approach established by the Army today ensures that there will be an in-depth evaluation of alternative routes for the pipeline and a closer look at potential impacts,” Interior Secretary Sally Jewell said in an e-mail. Energy Transfer owns the project with Phillips 66 and Sunoco Logistics. Marathon Petroleum Corp. and Enbridge Energy Partners LP announced a venture in August that would also take a minority stake in the pipeline.