The Keystone XL pipeline will not be completed this year.
The United States administration has ignored the Canadian government's demand for a decision soon on the controversial pipeline, so that construction could begin this summer.
The administration has released a statement announcing another delay in a project already beset by political and legal complications.
The announcement from the State Department says eight federal agencies have been informed that they will have more time to weigh in, given the uncertainty created by a court dispute in Nebraska.
Congressional staffers have also been informed, via conference call, about the delay caused by the Nebraska legal case. That case is not expected to be resolved until the end of this year, at the earliest.
There had been speculation about whether the Obama administration might try to punt the politically sensitive decision until after this year's midterm elections.
While the project appears to have support from the general public, it has divided Barack Obama's Democratic party, pitting big-money environmentalist donors against red-state conservative Democrats afraid of losing their congressional seats this fall.
In an attempt to push the process along, Foreign Affairs Minister John Baird spent several days in Washington recently pleading for a decision soon, arguing that it would be unfair to keep construction workers and the industry hanging as the building season approached.
But the project was tossed into further disarray by a recent Nebraska court ruling that the state government there broke the law in its attempt to unilaterally dictate a route.
The case is being appealed to the state supreme court. Until then, even a presidential permit to allow the pipeline to cross the border would slam into uncertainty given the confusion over the route.
For the time being, pipeline opponents argue, there is no legal route through Nebraska.
The southern leg of the Alberta-to-Texas pipeline is already completed, but the northern stretch that crosses the Canada-U.S. border requires a presidential permit. With that process delayed, rail shipments of Alberta crude have skyrocketed, threatening a broader trickle-down effect throughout the transportation system.