After being delayed for several months due to public opposition, the $3.8 billion (3.5 billion euro) pipeline is to be granted a final permit. It will tunnel under Lake Oahe, a reservoir that is part of the Missouri River.

The US Army Corps of Engineers filed a court document on Tuesday confirming it would grant the final permission for the 1,885-kilometer (1,170-mile) line that will bring crude oil from North Dakota's Bakken shale region to Patoka, Illinois, and then on to the Gulf of Mexico.

In a statement, the Army said it had completed a review ordered by the Obama administration and saw no reason to delay the project on environmental grounds.

The Army has "notified Congress that it intends to grant an easement for a right-of-way across government land at Lake Oahe Dam and Reservoir, North Dakota," it said.

Legal repercussions threatened

Within minutes of the filing, the Standing Rock Sioux tribe, whose reservation is adjacent to the line's route, confirmed it would launch a legal challenge.

Tribal attorney Jan Hasselman said the government "will be held accountable in court." He said the specifics of the tribe's challenge were being worked out.

The tribe is worried that a pipeline leak could pollute its drinking water. It believes that other routes should be considered.

Environmental groups including the Sierra Club, Greenpeace and the Center for Biological Diversity immediately denounced the US Army Corps of Engineers' decision. They accused US President Donald Trump's administration of putting corporate profits before long-time residents and the environment.

'Pipeline is vital'

But Dallas-based developer Energy Transfer Partners, who is building the pipeline, insists it is safe, while politicians in North Dakota are backing its completion, saying it will allow US producers to better compete with Canada by allowing for the cheaper transport of oil.

Over the past few months, thousands of demonstrators have camped in freezing winter temperatures to block the pipeline's planned route. At times, their rallies led to violent clashes with police as well as demonstrations nationwide.

The protests resulted in the Obama administration's decision to delay a final permit that would allow construction under the Missouri River.

But President Donald Trump, days after being sworn in, issued an executive order directing the US Army Corps of Engineers to smooth the path to finishing the line.

mm/jm (AFP, AP, Reuters)