Washington - The United States indefinitely extended the review process for a controversial Canada-to-US oil pipeline Friday, potentially delaying a final decision on the project until beyond mid-term elections in November.
The US State Department said eight federal agencies - which had been given until the end of May to submit views on the matter - would now have a longer window to weigh in on the long-delayed Keystone XL pipeline.
The pipeline, first proposed in 2008, is slated to cross US borders bringing oil from the tar sands of Alberta to refineries in the US state of Nebraska and then farther south to Texas.
Canadian Prime Minister Stephen Harper expressed disappointment that "politics continue to delay" a decision on Keystone, his spokesman Jason MacDonald said.
"This project will create tens of thousands of jobs on both sides of the border, will enhance the energy security of North America, has strong public support and the US State Department has, on multiple occasions, acknowledged it will be environmentally sound," the statement added.
The project has pitted environmental groups against the oil industry, which has argued that it will bring much-needed jobs to the United States and help fulfill the US goal of energy self-sufficiency.
Analysts say President Barack Obama, who has the final say on the pipeline, is caught in a classic no-win dilemma -- facing the prospect of losing votes in critical November 4 mid-term elections whatever he decides.
The State Department said that an ongoing legal wrangle in Nebraska, where a judge ruled in February that the proposed route of the 1 900km pipeline was unconstitutional, was partly responsible for the delay.