The president had tweeted his intent to issue the permit on Friday, based on the recommendations of Alaska Senator Dan Sullivan and Congressman Don Young, before officially granting the A2A Rail project the go-ahead on Monday.
The permit issues A2A Rail permission to "construct, connect, operate, and maintain railway facilities at the international border of the United States and Canada."
The project would build a new rail line from Fort McMurray, Alta., through the Northwest Territories and Yukon to the Delta Junction in Alaska, where it will connect with existing rail and continue on to ports near Anchorage.
The 2,570-kilometre railway could move cargo like oil, potash and ore, container goods, or even passengers.