President Trump has signed an executive action that will move the construction of the Dakota Access and Keystone XL pipelines forward, despite the months of protests by Native American and other activists at the North Dakota site insisting that the pipeline will cause major environmental damage.

Former President Barack Obama stopped the proposed Keystone XL pipeline in late 2015, declaring it would have undercut U.S. efforts to clinch a global climate change deal that was a centerpiece of his environmental legacy. The pipeline would run from Canada to U.S. refineries in the Gulf Coast. The U.S. government needed to approve the pipeline because it crossed the border.

Separately, late last year, the Army Corps of Engineers declined to allow construction of the Dakota Access pipeline under Lake Oahe, saying alternative routes needed to be considered. The Standing Rock Sioux tribe and its supporters say the project threatens drinking water and Native American sites, though Energy Transfer Partners, the company that wants to build the $3.8 billion pipeline, disputes that and says the pipeline will be safe.

Trump’s move on Tuesday effectively reverses Obama’s and the Corps’ actions.

Sen. Bernie Sanders was among the first to criticize the executive order, accusing Trump of putting profits ahead of the environment.

“At a time when the scientific community is virtually unanimous in telling us that climate change is real…we cannot afford to build new oil pipelines that lock us into burning fossil fuels for years to come.”

No response has been released yet from the Standing Rock tribe, but on Sunday, its leaders posted a Facebook message asking protesters to leave the encampment at Cannonball, N.D., which stood as host to demonstrators who attempted to push back against the construction of the project.

It is unclear what direction the protests will take, if any, now that Trump has issued the executive order. However it will likely leave environmental advocates furious and eager to combat the administration on other similar issues.

Former vice-president Al Gore, who has met with Trump on environmental concerns prior to his inauguration, called the Keystone XL pipeline “an atrocity” at the Sundance Film Festival where he debuted his film “An Inconvenient Sequel.”

Meanwhile, about 52,000 gallons of oil were spilled on First Nations land in Canada in a pipeline breach last week, according to officials. The leak spilled onto agricultural land near Stoughton, Saskatchewan. It was the second large pipeline oil spill in the province within the last seven months.

An earlier version of this story appeared on