The Canadian firm behind the controversial Keystone XL pipeline reapplied Friday for a presidential permit to ship crude oil from the oil sands fields of Alberta to the United States, reigniting a national debate over how to meet the nation’s energy needs.

In January, the Obama administration denied a permit to Trans­Canada, the firm that would build the project, on the grounds that a congressionally mandated deadline of Feb. 21 did not give officials enough time to evaluate the pipeline’s impact. Since then, TransCanada has said it would proceed with plans to construct a segment that did not require a presidential permit — from Cushing, Okla., to Port Arthur, Tex.

In a statement issued Friday, the State Department said TransCanada’s application included “new routes,” though it did not identify them, and said it would examine whether the project “is in the national interest.”

This determination process — which the agency said “involves consideration of many factors, including energy security, health, environmental, cultural, economic, and foreign policy concerns” — would probably be complete by April 2013, according to the statement.

The Keystone pipeline project, a point of contention between environmentalists and some labor unions, has divided the Democratic base. It has unified Republicans behind what they contend is a critical source of energy for the United States. Presumptive Republican nominee Mitt Romney, along with GOP congressional leaders, has called on Obama to approve the pipeline.

Proposed Keystone XL Extension map

The company unveiled one new route for the pipeline through Nebraska last month. President Obama, environmentalists and many Nebraskans — including the state’s Republican governor, Dave Heineman — had raised concerns that the project’s original route could imperil Nebraska’s ecologically sensitive Sand Hills region, as well as the Ogallala aquifer, a major source of drinking water for state residents.

Last month Heineman signed a bill enabling his state to go ahead with its review of the project, regardless of federal action on the pipeline.

The new route would steer clear of the Sand Hills region, although it still runs over parts of the Ogallala aquifer. Environmentalists say that Nebraska officials have defined the Sand Hills region too narrowly and that the revised route will traverse the Sand Hills in Nebraska’s northern Holt County.

The State Department has jurisdiction over the pipeline permit because the project crosses an international border. The original pipeline was slated to run 1,700 miles from Hardisty, Alberta — an area known for oil sands or tar sands — to Port Arthur. In Canada, operators extract a viscous oil called bitumen from formations of sand, clay and water, using a process that consumes more energy and water than conventional drilling. NASA researcher James E. Hansen and other scientists have warned that oil sands activity could accelerate global warming to dangerous levels.

TransCanada chief executive Russ Girling had a closed-door meeting Thursday with Kerri-Ann Jones, the assistant secretary of state who oversaw the original presidential permit application. In a statement Friday, Girling said, “The multi-billion dollar Keystone XL pipeline project will reduce the United States’ dependence on foreign oil and support job growth by putting thousands of Americans to work.”

Both Republicans and some union leaders urged Obama to approve the presidential permit Friday.

House Speaker John A. Boehner (R-Ohio) issued a statement saying, “Today there is just one person standing in the way of tens of thousands of new American jobs: President Obama. After nearly four years of review, delay, and politics, he is out of excuses for blocking this job-creating energy project any longer.”

“It’s time to put politics aside and put thousands of construction workers back to work,” said International Union of Operating Engineers General President James T. Callahan in a statement.

Environmentalists made it clear after the announcement they would continue to oppose the project.

“Tar sands are the world’s dirtiest form of oil, require a devastating process that lays waste to forests to extract tar sands bitumen, a thick low grade fuel that has significantly higher emissions [than] conventional crude,” wrote Anthony Swift, an attorney in the Natural Resources Defense Council’s international program in a blog post. “Tar sands pipelines also appear to pose higher risks — both in number and severity of pipeline spills.”

The lower segment of the pipeline, from Oklahoma to Texas, is backed by Obama and congressional Republicans. It would cost $2.3 billion to build, transport 700,000 barrels a day starting in mid-to-late 2013 and alleviate a glut of oil at Cushing, a major energy terminal.

TransCanada is moving ahead on obtaining permits needed to build the Oklahoma-Texas leg of the pipeline, having recently submitted applications to district offices of the Army Corps of Engineers in Tulsa, Fort Worth and Galveston.

If the Corps does not respond within 45 days, the permits are automatically approved and construction can proceed, according to federal law.

An Environmental Protection Agency official has raised questions about whether that leg of the project qualifies for such an expedited review.

In a Nov. 8 letter to the Corps’ Galveston office, Jane Watson, associate director of ecosystems protection for the EPA’s Region VI, said the project warrants a more detailed environmental assessment.