Bismarck - The acting secretary of the Army has ordered the Army Corps of Engineers to allow construction of the Dakota Access pipeline under a Missouri River reservoir, a North Dakota senator said, the latest twist in the months-long legal battle over the $3.8bn project.
The Standing Rock Sioux, whose opposition to the project attracted the support of thousands of protesters from around the country to North Dakota, immediately vowed to return to court to stop it.
Senator John Hoeven, a Republican, announced that Robert Speer directed the Army Corps of Engineers to "proceed" with an easement necessary to complete the pipeline. President Donald Trump signed an executive order signalling his support for the project a week ago.
Army spokesperson Major General Malcolm Frost said on Wednesday that the Army had begun its review.
"These initial steps do not mean the easement has been approved," Frost said.
However spokesperson Don Canton said Speer's move meant the easement "isn't quite issued yet, but they plan to approve it" within days.
The crossing under Lake Oahe, a wide section of the Missouri River in southern North Dakota, is the final big chunk of work on the pipeline designed to carry North Dakota oil through South Dakota and Iowa to a shipping point in Illinois.
The pipeline has been the target of months of protests led by the Standing Rock Sioux, whose reservation lies near the pipeline's route and who have argued that it's a threat to water and tribal artifacts.
The tribe has vowed to challenge any granting of the easement in court and chair Dave Archambault renewed that vow.An environmental assessment conducted last year determined the crossing would not have a significant impact on the environment. However, then-Assistant Army Secretary for Civil Works Jo-Ellen Darcy on December 4 declined to issue an easement, saying a broader environmental study was warranted.