Standing alongside his secretaries of energy and commerce, Trump vowed that the pipeline would be the "first of many" energy projects his administration will approve.
The officials, who weren't authorized to speak publicly and demanded anonymity, said the State Department's recommendation and the White House's final approval would be Friday.
- Members of North Dakota's congressional delegation say they support the Trump administration's approval of the Keystone XL oil pipeline.
The proposed 1,200-mile pipeline would allow crude oil from Canada's oil-sands region to be transported to refineries on the Gulf Coast.
Environmental groups are wary that the pipeline will rely on Canadian oil sands, a dirtier form of oil that releases more greenhouse gases than standard oil extraction.
Part of the original Keystone pipeline runs through eastern Nebraska. On his second day in office, this President made it his priority to push through two controversial pipelines.
"I'm sure we're going to see blockades like we saw with the Dakota Access Pipeline".
Keystone pipeline would create about 3,900 construction jobs if it was built in one year, according to a State Department report.
"The dirty and risky Keystone XL pipeline is one of the worst deals imaginable for the American people, so of course Donald Trump supports it", Michael Brune, executive director of the Sierra Club, said in a statement.
The $8 billion project is projected to create more than 42,000 American jobs building critical energy infrastructure.
"Investors should be very anxious about the risky financials and lack of social licence attached to pipeline projects across both countries", said Greenpeace campaigner Mike Hudema in a statement.
Talk of challenges facing Keystone XL - legal or political - are not surprising, said Dirk Lever at AltaCorp Capital.
While oil and gas companies have welcomed Mr. Trump's support of energy infrastructure projects, his assertion that such projects must use USA steel has confounded them. Legislators write to then-secretary of state Hillary Clinton calling for greater environmental oversight; scientists begin speaking out against the project; and the Environmental Protection Agency questions the need for the pipeline extension. But his administration has already given Keystone a pass. TransCanada has already acquired the steel for the project, and the White House has said it's too hard to impose Trump's requirement on a project already under construction.
Girling said in the White House gathering that TransCanada "had some work to do" to secure permits in the state.
Trump did not repeat an earlier promise that the steel to make the Keystone XL pipeline would be American.
Portions of Keystone have already been built.
"Resistance spirit camps" are expected to be erected along the Keystone XL route similar to the camps established by Dakota Access Pipeline opponents in North Dakota, said Dallas Goldtooth, an organizer with the Indigenous Environmental Network.