Some protesters are skeptical of government’s decision to refuse permission for controversial oil pipeline project.

A Native American leader has asked thousands of protesters to return home after the federal government ruled against a controversial pipeline, despite the prospect of President-elect Donald Trump reversing the decision.

A coalition of Native American groups, environmentalists, Hollywood stars and veterans of the US armed forces protested against the $3.8bn Dakota Access Pipeline project, arguing that construction would damage sacred lands and any leaks could pollute the water supply of the Standing Rock Sioux tribe.

On Monday, the US Army Corps of Engineers turned down a permit for the project running through North Dakota but the tribe still wants to speak to Trump and prevent him from approving the final phase of construction, Standing Rock Sioux Chairman Dave Archambault said.

North Dakota pipeline project halted

“The current administration did the right thing and we need to educate the incoming administration and help them understand the right decision was made,” Archambault told Reuters news agency.

On Monday, Trump’s transition team said it would review the decision to delay completion once he takes office on January 20.

Archambault said nothing would happen over the winter before Trump takes office, so protesters should leave.

“We’re thankful for everyone who joined this cause and stood with us,” he said.

“The people who are supporting us … they can return home and enjoy this winter with their families. Same with law enforcement. I am asking them to go.”

It was unclear if protesters would heed Archambault’s call to leave the Oceti Sakowin camp in Cannon Ball, North Dakota.

IN PICTURES: Protesters celebrate as army halts Dakota pipeline work

The Army Corps said it would analyse possible alternate routes, although any other route is likely to cross the Missouri River.

The camp celebrated the decision, but some expressed concern that their victory could be short-lived.

“I think this is just a rest,” said Charlotte Bad Cob, 30, of the Pine Ridge Reservation in South Dakota. “With a new government it could turn and we could be at it again.”

The company building the 1,885km pipeline, Energy Transfer Partners, said late on Sunday that it had no plans to reroute the line, and expected to complete the project.

The pipeline is complete except for a 1.61km segment that was to run under Lake Oahe, which required permission from federal authorities.