A decision on the Keystone XL pipeline will be delayed as federal U.S. agencies have been given more time to submit their views on the $5.3-billion project.

Despite pressure from Canada for an immediate decision on the controversial pipeline, the U.S. Department of State announced Friday that eight federal agencies need more time to weigh in on the project.

The State Department says the delay is due to the uncertainty created by a recent Nebraska court ruling that said that state's government broke the law in its attempt to unilaterally dictate a pipeline route. The court case is not expected to be resolved until the end of this year, at the earliest.

The State Department also notes that it has received an "unprecedented" number of public comments – about 2.5 million – that it will have to review.

"The agency consultations process is not starting over," the State Department said in a statement. "The process is ongoing, and the department and relevant agencies are actively continuing their work in accessing the permit application.

The Prime Minister's Office also weighed in Friday, saying it is disappointed about the delay.

"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 U.S. State Department has, on multiple occasions, acknowledged it will be environmentally sound," PMO spokesperson Jason MacDonald said in a statement.

TransCanada, the Calgary-based company behind Keystone, said another delay in the pipeline decision is "inexplicable," as Americans will miss out on another construction season where they could have worked to build Keystone XL.

"We feel for them," TransCanada CEO Russ Girling said in a statement.

Girling said Canada is a stable and secure source of oil. He noted that the first leg of the Keystone pipeline – which took 21 months to study and approve – began shipping oil in 2010.

"After more than 2,000 days, five exhaustive environmental reviews and over 17,000 pages of scientific data Keystone XL continues to languish," he said.

Girling said Canadian oil will make its way to market, "with or without Keystone XL."

Ottawa has pushed the United States administration to make a decision on the project, which, if approved, would carry more than 800,000 barrels of crude oil from western Canada through the U.S. heartland to refineries on the Texas Gulf Coast.

Alberta Premier Dave Hancock said the project is in North America's best interest, as it will provide the U.S. with a dependable energy source from a democratic and friendly ally.

He also noted that Keystone's approval would provide Canadians with more job opportunities.

"Alberta's commitment to responsible environmental management strongly positions us as the safest and most secure energy supplier to our American neighbours," Hancock said in a statement.

During a recent visit to Washington, Foreign Affairs Minister John Baird pushed U.S. politicians to make a timely decision on Keystone.

However, U.S. Secretary of State John Kerry said at the time the government will not put a timeline on when it will hand down a decision on the controversial pipeline.

U.S. pipeline supporters, including lawmakers from both the Republican and Democratic parties and many business and labour groups, say the project would create thousands of jobs and reduce the need for oil imports from Venezuela and other politically turbulent countries. Opponents say the pipeline would carry "dirty oil" that contributes to global warming. They also worry about possible spills.

Environmentalists respond

Following the State Department's announcement, a number of environmental agencies said they're holding U.S. President Barack Obama accountable to his promise to tackle climate change.

"The tar sands are high cost, high risk and high carbon and this is another clear signal that their future is anything but certain," Hannah McKinnon of Environmental Defence said in a statement. "The tar sands have a devastating impact on land, air, water, communities and our shared climate and it is critical that the President get it right and reject this pipeline." 

Greenpeace Canada said the Keystone project "fails the (U.S) President's climate test," as it will accelerate damage to the environment.

"The Alberta government should use this delay to wake up to the urgent reality of the climate crisis and the fact we need to start keeping more tar sands in the ground not pumping more out of it," Mike Hudema said in a statement. "The Alberta government need to start acting, because delay when it comes to climate change simply isn't a morally defensible option."

Meanwhile, Republican House Speaker John Boehner on Friday called the delay "shameful."

"With tens of thousands of American jobs on the line and our allies in eastern Europe looking for energy leadership from America, it's clear there is little this administration isn't willing to sacrifice for politics," he said in a statement.