(Adds comment from White House)
By Ros Krasny
WASHINGTON, April 10 (Reuters) - Eleven U.S. Democratic senators urged President Barack Obama on Thursday to make a final decision on whether to approve TransCanada Corp's Keystone XL crude oil pipeline from Canada to the U.S. Gulf Coast no later than May 31.
"We need a definitive timeline laid out, a timeline that reduces the comment period for federal agencies, officials and other entities," the senators wrote to Obama. "We cannot miss another construction season."
The group included several lawmakers expected to face tough re-election battles this year, notably Mary Landrieu of Louisiana, who chairs the Senate Energy Committee.
Also signing on were Heidi Heitkamp of North Dakota, Mark Begich of Alaska, Joe Donnelly of Indiana, Kay Hagan of North Carolina, Joe Manchin of West Virginia, Claire McCaskill of Missouri, Mark Pryor of Arkansas, Jon Tester and John Walsh, both of Montana, and Mark Warner of West Virginia.
Responding to the letter, White House spokesman Jay Carney said the administration did not intend to change the trajectory of its Keystone review, which is presently in the hands of the State Department.
"Our position on that process hasn't changed, which is it needs to run its appropriate course without interference from the White House or Congress," Carney told reporters aboard Air Force One on Thursday. "When there's a decision to be announced, it will be announced."
The proposed 1,179-mile (1,898-km) line, which would transport crude from Alberta to refineries on the Gulf Coast, has been under U.S. government review since 2008.
Opponents say the pipeline would exacerbate climate change by supporting carbon-intensive development of Canada's oil sands crude. Supporters in Congress and the energy industry say Keystone would improve U.S. energy security and create thousands of construction jobs.
The State Department issued an environmental assessment of the project Jan. 31 that ran to more than 2,000 pages, kicking off a 90-day comment and consultation period during which certain federal agencies can weigh in with their own views.
The senators' letter said that once that comment period ends, Obama should require Secretary of State John Kerry to make a final interest determination recommendation within 15 days, and follow with his own decision shortly after.
"This process has been exhaustive in its time, breadth and scope. It has already taken much longer than anyone can reasonably justify," they said.
TransCanada shares were up 0.7 percent at C$51.21 in Toronto trading on Thursday afternoon.
(Additional reporting by Roberta Rampton in Washington; editing by Lisa Von Ahn, Bernadette Baum and Matthew Lewis)