Washington, February 9 (RHC)-- The U.S. Army Corps of Engineers has announced it will greenlight the final phase of construction for the Dakota Access pipeline, prompting indigenous water protectors and their allies to call for a "last stand" against the $3.8 billion project. 

In a letter to the U.S. Congress, acting Army Secretary Robert Speer said the Army Corps will cancel an environmental impact study of the Dakota Access pipeline and will grant an easement allowing Energy Transfer Partners to drill under Lake Oahe on the Missouri River. 

The Army Corps also said it would suspend a customary 14-day waiting period following its order, meaning the company could immediately begin boring a tunnel for the final one-and-a-half miles of pipe.  

The Standing Rock Sioux Tribe has promised a legal battle and Tribal Council Chair Dave Archambault II said in a statement: "As Native peoples, we have been knocked down again, but we will get back up, we will rise above the greed and corruption that has plagued our peoples since first contact.  We call on the Native Nations of the United States to stand together, unite and fight back." 

Other indigenous water protectors and their allies have vowed to take direct action to stop construction at the drill pad on the west bank of the Missouri River, less than a mile north of the Standing Rock Reservation.  Activists are also planning solidarity actions in cities across North America and around the world.