Alberta-based TransCanada disputed Mr. Obama's claim that the project's jobs creation would be "a blip relative to the need," pointing to research by the administration showing that Keystone could create more than 40,000 jobs.
For that reason, Keystone has been touted by divisions of the AFL-CIO and other labor groups, key constituencies of the president.
Mr. Obama's seemingly low jobs figures have led some critics to question whether he is familiar with his administration's data on Keystone.
"Has President Obama read his own State Department's" report? said a blog posted Monday on the Oil Sands Fact Check website. The organization is supported by energy companies, chambers of commerce, manufacturers and others and describes itself as devoted to "checking facts and providing the proper context" with regard to Canadian oil sands.
"President Obama should rely on the data from the experts at the State Department who have been studying this project for nearly five years instead of opponents whose goal in life is to shut down the energy development that creates thousands of jobs, fuels our economy and keeps gas prices low," the blog said.
Just a month after hinting that he would approve the Keystone XL oil pipeline, Mr. Obama told The New York Times that the $7 billion project won't carry the economic benefits or create the thousands of jobs its supporters suggest. He also said it's unlikely to lower U.S. gas prices.
"Republicans have said that this would be a big jobs generator. There is no evidence that's true," Mr. Obama said over the weekend. "The most realistic estimates are this might create maybe 2,000 jobs during the construction of the pipeline, which might take a year or two, and then after that we're talking about somewhere between 50 and 100 jobs in an economy of 150 million working people."
He added that 2,000 jobs were "a blip relative to the need."
The interview marked the latest chapter in the ongoing Keystone debate, which has dragged on since the president came into office into 2009.
House Speaker John A. Boehner, Ohio Republican, and a growing bipartisan coalition on Capitol Hill are ardent supporters of the project, and several members of Congress wasted little time in pouncing on the president's comments.
"What will it take for our president to focus on job creation and not job killing?" said Rep. Lee Terry, Nebraska Republican. If built, the Canada-to-Texas pipeline would run through his state.
"President Obama needs to spend more time working with Republicans in Congress rather than traveling around the country reciting the environmental left's talking points and giving speeches that don't hire," Mr. Terry added.
Mr. Obama's remarks added more confusion to the debate surrounding Keystone, one in which Mr. Obama seemingly has moved the goal posts.
In his widely hyped speech on climate change last month, the president said the pipeline — which would carry Canadian oil sands through the U.S. heartland en route to Gulf Coast refineries — should be approved only if it doesn't exacerbate the problem of carbon pollution.
Mr. Obama's own State Department has said the project won't significantly increase greenhouse gas emissions because the Canadian fuel is likely to be extracted and burned regardless of whether Keystone is built.
The Canadian government, a frequent critic of the White House's years of indecision on Keystone, went a step further, charging that even if Mr. Obama rejects Keystone, he still won't be able to keep the fuel off of U.S. soil.
"His choice is to have [the oil] come down by a pipeline that he approves, or without his approval, it comes down on trains. That's just the raw common sense of this thing, and we've been saying it for two years and we've been proven correct," Canadian Ambassador Gary Doer told the Globe and Mail newspaper. "At the end of the day, it's trains or pipelines."
While the northern portion of the pipeline — which would stretch from Albert to Steele City, Okla. — has been on hold for about five years, the southern leg is nearly complete. That section, running from Oklahoma to the Gulf Coast, has created about 4,000 jobs — double the figure cited by Mr. Obama.
"I think the Americans we have put to work so far appreciate the fact they have been able to put food on the table for their families by helping to build Keystone," said Shawn Howard, TransCanada spokesman.
Mr. Obama made the comments as he is trying to set the stage for budget and debt negotiations with House Republicans in September.
In spite of the Keystone controversy, Mr. Obama will travel Tuesday to Chattanooga, Tenn., where he will promote economic policies to create middle-class jobs, said White House deputy press secretary Josh Earnest.
"He's talking about his view that when we're making economic policy decisions in Washington, D.C., we need to put the interests of the middle-class families front and center," Mr. Earnest said. "If we can make the kind of investments that will expand economic opportunity for the middle class, then we can get a growing and thriving economic recovery and ... that should be everybody's priority."