CALGARY - TransCanada Corp. has stepped up its publicity campaign for the politically charged Keystone XL pipeline, releasing a detailed breakdown of where the $7-billion project would create 20,000 jobs in the United States, if approved.

The project requires presidential approval but Keystone is a major challenge for the Obama administration in an election year because of opposition from environmental groups.

U.S. President Barack Obama faces a Feb. 21 deadline to decide whether the pipeline is in the national interest.

TransCanada and its supporters, including Prime Minister Stephen Harper, have argued for months that the Keystone XL pipeline from Alberta to the Gulf Coast is vital to the United States because it will provide energy security and jobs.

"These are new, real U.S. jobs," said Russ Girling, TransCanada's president and chief executive officer, in a statement Tuesday.

He said 13,000 Americans would be put to work constructing the pipeline and pumping stations and 7,000 more jobs would be created in the U.S. manufacturing sector.

TransCanada also itemized the 27 types of jobs that will be needed for each of the 17 construction segments -- everything from one environmental co-ordinator and two welding foremen to 111 labourers and 152 operators.

TransCanada says it has contracts with over 50 suppliers across the country, some of them in important political battlegrounds for this year's elections.

It says there are manufacturing locations for its equipment in Texas, Missouri, Pennsylvania, Michigan, Oklahoma, South Carolina, Indiana, Georgia, Maryland, New York, Louisiana, Oklahoma, Minnesota, Ohio, Arkansas, Kansas, California and Pennsylvania..

Originally, TransCanada had expected to receive approvals from the U.S. State Department -- required because the pipeline crosses an international boundary -- by the end of 2011.

But the department said in November, amid widespread protests by environmentalists and others opposed to the pipeline, that it would delay its decision until after the 2012 presidential election.

Since then Congress has passed, and Obama has signed, a bill that gave his administration 60 days to make a decision.

During a speech Tuesday in Oklahoma City, Robert Jones, TransCanada's vice-president for Keystone Pipelines, said Canadian oil producers will look to Asian markets if the U.S. government fails to approve the Keystone XL pipeline project.

But Jones said he believes it makes more sense to keep Canadian oil in North America because it is more efficient and benefits both the United States and Canada.

TransCanada's announcement on Tuesday coincided with two politically charged events -- the New Hampshire Republican primary and the start of Canadian public hearings into another controversial proposal, the Enbridge Northern Gateway pipeline project between Alberta and the B.C. coast.

More than 4,300 individuals and groups have registered to speak at the hearings conducted by two federal environmental bodies over the next 18 months or more across British Columbia and Alberta.

Federal regulatory hearings have begun in Kitimat, B.C.