Opponents of the Dakota Access pipeline are calling for protests around the world as the Army prepares to greenlight construction of the final stage of the project.
The Army on Tuesday said it will allow the pipeline to cross under a Missouri River reservoir in North Dakota, clearing the way for completion of the $US3.8 billion ($A5.0 billion) project to move North Dakota oil to Illinois.
Some opponents who worry the pipeline will harm the environment have dubbed Wednesday "#NODAPL Last Stand" day, and they're calling on social media for "emergency actions." A list shows events planned across the US and in Canada.
The call is coming from Standing Rock Sioux members. The tribe says a pipeline leak could contaminate its drinking water. Project developer Energy Transfer Partners says the pipeline is safe.
