The US State Department is giving federal agencies more time to review the Keystone XL oil pipeline before it decides whether to issue a permit. They previously had until late May to do so.
The BBC reports the delay suggests a decision on whether to approve the pipeline could come after the elections in November.
The state department raised no major environmental objections to the pipeline in a report released in February.
The White House stalled the pipeline project in 2011 amid concerns about damage to the environment along the route.
The 1408km pipeline would carry some 830,000 barrels of heavy crude a day from Alberta, Canada, to Nebraska.
The oil would then be pumped on existing pipes to refineries in Texas. The southern section of the project was finished last year.