Pipeline company TransCanada said it aims to replace sections of the Keystone oil pipeline in the United States so it can operate at a higher pressure.

TransCanada spokesman Terry Cunha told the Lincoln (Neb.) Journal Star sections running through Illinois, Kansas, Missouri, Nebraska and South Dakota would be replaced so the pipeline meets federal standards necessary for higher pressures.

Keystone operates at about 70 percent of the pressure that would deform the system, but in 2007, TransCanada got approval to run at 80 percent provided it meets a variety of safety regulations. Operating at a higher pressure "allows us to be more efficient with our operations to meet customer expectations and demands," Cunha told the newspaper.

The company in April reported about 400 barrels of oil leaked from a section of the pipeline running through South Dakota. The company closed the pipeline for about a week, but was allowed to restart operations at a reduced rate according to the terms of an order from the federal Pipeline and Hazardous Materials Administration.

Bold Nebraska, an advocacy group opposed to TransCanada, said an area farmer discovered the April leak before TransCanada's systems were triggered. According to Bold Nebraska, the April 2 spill was the 30th spill from the Keystone system since it launched in 2010.

The Keystone pipeline runs from Alberta, Canada, to terminals in Cushing, Okla., and Wood River, Ill.

TransCanada's permit to build Keystone XL, an extension of the original pipeline, was denied by the U.S. government in November on environmental grounds. TransCanada in January launched a legal challenge against the decision.

Early critics of the project pointed to a history of breaks along the current route and raised concerns about the potential harmful environmental impact of heavy crude oil from Alberta.