Just last week 76 protesters were arrested after refusing to leave land owned by the energy company. Photo: Getty Images

The notice comes a month after Donald Trump formally backed the project in one of his first acts as US president.

Thousands of predominantly Native American protesters have boycotted the $3.8bn (£3bn) pipeline's construction in the state of North Dakota.

The Standing Rock Tribe vowed to fight the decision in court.

The 1,172 mile (1,886km), four-state project is almost complete except for a one-mile stretch under Lake Oahe in North Dakota, where demonstrators have set up protest encampments.

The Army's statement on Tuesday said: "The Department of the Army announced today that it has completed a presidential-directed review of the remaining easement request for the Dakota Access pipeline, and has notified Congress that it intends to grant an easement."

Easement is a special permit that allows a company to cross private land.

Standing Rock Sioux lawyer Jan Hasselman said the government "will be held accountable in court".

But North Dakota's two US senators, both Republicans, welcomed the Army's announcement.

Heidi Heitkamp said the decision brought "certainty and clarity", while John Hoeven said the pipeline would serve the nation's need for new energy infrastructure.

Environmental groups, including Greenpeace, the Sierra Club, and the Center for Biological Diversity, issued statements criticising the decision.

They accused the Trump administration of putting corporate profits ahead of Native Americans and the environment.

Nearly 700 people have been arrested since protests first began last year, according to law enforcement officials.

Just last week 76 protesters were arrested after refusing to leave land owned by the energy company.

The proposed crossing point for the pipeline is upstream from the tribe's territory, raising fears that any rupture could threaten drinking water supplies.

The pipeline's owner, Dallas-based Energy Transfer Partners, says the project is safe.

In September, the Obama administration announced that it would not allow the project to proceed.