Trump on Monday false claimed during remarks to business leaders in Tokyo that construction for the controversial pipeline is underway, even though the project hasn't found buyers yet.
Over the past year oil companies have discovered volumes on Alaska's North Slope totaling as much as five billion barrels or more of recoverable oil.
The move would mark the beginning of a process that could be lengthy. Approvals are needed from state regulators, and the project could face legal challenges.
Protesters were set to gather in a number of U.S. cities on Wednesday, a day after the U.S. Army said in a legal filing it planned to cancel an environmental study and grant the final easement needed to complete the Dakota pipeline.
While oil producers in Canada and North Dakota are expected to benefit from a quicker route for crude oil to U.S. Gulf Coast refiners, a revival of the projects would mark a bitter defeat for Native American tribes and climate activists.
With a global climate change summit looming, so are fights over Obama proposals.
"The pipeline would not make a meaningful long-term contribution to our economy," the president said.
The decision is expected to lead to the project's rejection by the Obama administration.
The president has increasingly signaled the $8 billion pipeline may not be approved.
A delay would almost certainly hand the decision for the $8 billion project to a future president.
She called the pipeline a "distraction."
The controversial project now awaits an administration decision on whether to permit or deny it.
The temporary injunction was prompted by a lawsuit from 70 landowners who don't want the pipeline on their property.
A final decision from the President could come as early as February.
The Nebraska Supreme Court's decision reversed a lower court that had blocked the proposal and cleared the way for a U.S. State Department ruling on the plan.
President's former press secretary hints that Obama may veto the pipeline.
In a 59 to 41 vote, the U.S. Senate narrowly voted to reject the Keystone XL pipeline Tuesday evening after several hours of intense debate.
Obama cited pending legal action in Nebraska and said it was hard to evaluate the pipeline proposal until the actual route was known.