TransCanada says it has refiled an application in Nebraska seeking approval for the Keystone XL pipeline route through the state, a hotbed of opposition to the project.

The company says the application with the Nebraska Public Service Commission is the clearest path to achieving route certainty, adding that it expects a decision on its application by the end of the year.

It says the proposed route was approved by the governor of Nebraska in 2013 and its application has been shaped by "direct, on-the-ground input from Nebraskans."

Nebraska has been the site of some of the fiercest opposition to Keystone XL due to concerns that a spill could contaminate the Ogallala Aquifer.

TransCanada says the pipeline would avoid the Nebraska Sandhills area of the state under which the aquifer sits.

The company filed a presidential permit application for the project late last month after being invited to by President Donald Trump, who has asked that the review process be done quickly.