The decision comes after President Donald Trump gave the order to expedite the $3.8 billion project that faces opposition from Native American tribes and environmental activists.
US authorities said on Tuesday they will approve a permit to complete the controversial Dakota Access pipeline, despite months of protests by Native American tribes and environmental activists.
The decision comes following last month's order from President Trump to expedite the $3.8 billion pipeline, which would snake through four US states.
The Army Corps of Engineers, which has approval authority, said on Tuesday, it had "completed a presidential-directed review" and planned to grant permission for the pipeline's construction.
The project is close to completion as it only requires building of a tunnel under Lake Oahe, a reservoir that is part of the Missouri River.
The reservoir is the drinking water source for the Standing Rock Sioux Tribe, which objects to the pipeline's routes.
Frances Read has more from Los Angeles.
Standing Rock Sioux tribe vows to shut pipeline down
The Standing Rock Sioux tribe vowed to challenge the decision to complete the project in the court.
Moreover, it said, if the pipeline was completed, the tribe would "seek to shut the pipeline operations down," adding, the environmental study was "wrongfully terminated."
The tribe had said the line would desecrate sacred sites and potentially pollute the tribe's water source.
Natural gas and propane company, Energy Transfer Partners, is building the 1,170-mile (1,885 km) line to pump crude from the shale oil fields of North Dakota to the Gulf of Mexico, where many US refineries are located.
The line could be operational by June if the permit comes quickly.