Mr. Obama has repeatedly resisted efforts by Republicans to force him to speed up the approval process for the pipeline. During the 2012 election campaign, Mr. Obama faced blasts of criticism from pipeline supporters, including Mitt Romney, his Republican opponent, who said he should make a decision quickly and insisted that the pipeline project would help create American jobs.

Earlier this year, environmentalists expected that Mr. Obama would approve the pipeline. But in a speech at Georgetown University in June, Mr. Obama made it clear that he would approve the pipeline only if the reviews concluded that it did not “significantly exacerbate” the amount of carbon in the environment. “The net effects of the pipeline’s impact on our climate will be absolutely critical to determining whether this project is allowed to go forward,” he said then. “It’s relevant.”

On Tuesday, White House officials said Republicans were playing politics with the environment. “The president has demonstrated his fidelity to the State Department finishing its review, as part of the transparent and rigorous process that will determine whether the pipeline is in the best interests of the United States,” said Josh Earnest, a White House spokesman. “That’s how this merit-based determination will be made.”

But lawmakers like Mr. Terry, who is leading the effort among House Republicans to get the pipeline built, are impatient. “The majority of us in the House feel the president is doing everything he can to avoid moving this issue one way or another,” he said.

Mr. Terry said Republicans intended to press hard on the pipeline and would only give in on raising the debt ceiling if Mr. Obama made a clear deal on constructing the pipeline. “It couldn’t just be some commitment” by the president to look at the issue, Mr. Terry said. “There’s not a lot of trust on our side of the aisle,” he said. “It would have to be something rock solid, that the pipeline would be built.”

In his first term, Mr. Obama largely backed off legislative efforts to combat climate change even as he pushed tougher emissions standards for automobiles. Since being re-elected, the president has become more aggressive. Last week he announced new rules that would allow the Environmental Protection Agency to regulate the amount of carbon dioxide emitted from newly built power plants.

But the pipeline decision has become a cause for environmentalists, who say the pipeline would provide a reason for Canadian companies to extract huge amounts of oil from the Alberta tar sands. They argue that stopping the pipeline would limit the oil extracted and reduce carbon emissions from its use.