US President Donald Trump signed two executive actions on Tuesday to advance construction of the controversial Keystone XL and Dakota Access pipelines.
The decrees require the pipelines to be built with steel sourced from the US, according to reports.
"We are very insistent that if we are going to build pipelines in the United States, the pipes should be built in the United States," Trump was quoted as saying.
He told reporters that "we are going to renegotiate some of the terms" of the Keystone XL project. "And if they like, we will see if we can get that pipeline built."
He said the Dakota Access line would be "subject to terms and conditions negotiated by us".
Details of the orders were not immediately made public.
According to North Dakota Congressman Kevin Cramer, a Republican, one order directs all federal agencies, including the US Army Corps of Engineers, to expedite approval of the easement to complete construction of the Dakota Access Pipeline project.
Another order invites TransCanada to resubmit its Keystone application and directs the State Department to expedite its review.
"Today’s executive orders affirm President Trump's respect for the rule of law and his support for responsible infrastructure development, energy production and job creation," Cramer said in a statement.
The moves, which came on Trump's fourth full day in office, follows months of protests by environmentalists and Native American groups in North Dakota against Energy Transfer's $3.8 billion Dakota Access pipeline, which would bring crude oil from the state's Bakken shale region through the Midwest and into the US Gulf Coast.
The Keystone XL pipeline would bring crude from Alberta's oil sands across the US border and eventually to markets on the Gulf Coast. Environmentalists cheered in late 2015 when Trump's predecessor, Barack Obama, denied operator TransCanada a permit to build the cross-border pipeline.
"We are pleased to see the new direction being taken by this administration to recognize the importance of our nation's energy infrastructure," the American Petroleum Institute said in a statement.
Democratic Congressman Jared Polis of Colorado said it is "disheartening to see President Trump put the oil and gas industry ahead of the health of our planet, wellbeing of people, and – in the case of the Dakota Pipeline – sovereignty of Native Americans".
Neither Energy Transfer nor TransCanada had immediate comment on Tuesday.
Trump, who has been stridently pro-energy throughout the presidential campaign and following the election, had long telegraphed his intentions to advance projects like Dakota Access and Keystone XL.
On Friday, a North Dakota lawmaker said it was possible construction to finish the Dakota Access line could begin within a week.
The US Army Corps of Engineers in December denied the pipeline developer an easement to drill under Lake Oahe, a water source upstream from the Standing Rock Sioux reservation that has been the focus of months of fierce protests due to fears the pipeline could threaten to pollute drinking water and desecrate sacred grounds.
The Corps began the process of collecting information for an environmental impact statement last week.
Despite the executive action, the Standing Rock Tribal Council on Saturday passed a resolution asking that no activist camps remain in the area.
"We ask the protectors to vacate the camps and head home with our most heartfelt thanks," the council said in a statement.
