* Kerry: "I'll do my best to leave no question unanswered"
* Environment group criticized him for not speaking out
By Roberta Rampton
WASHINGTON, Oct 27 (Reuters) - Senator John Kerry said the U.S. Senate Foreign Relations committee is scrutinizing concerns raised about the Keystone XL pipeline and promised to try to "leave no question unanswered" about the project, which would carry oil from Canada to Texas.
Responding to criticism from an environmental group on Thursday, Kerry said committee staff have tracked the issue closely for two years, discussing environmental issues with the State Department.
"The Committee's ongoing work is obviously especially urgent given the concerns that have been raised and we're following up with the State Department and the White House," said Kerry, the influential chairman of the panel.
TransCanada Corp's $7 billion pipeline plan is at a critical political juncture. The State Department had planned to rule later this year on whether to allow the project, although a U.S. official told Reuters this week the timeline could slip.
"There's a lot at stake here and I'll do my best to leave no question unanswered, including every possible economic and environmental consideration, before a final decision is made," Kerry said in a statement.
Environmental groups have pushed the Obama administration to reject the project. Some 1,200 opponents of the line were arrested at the White House this summer and another protest is scheduled there on Nov. 6.
A group of 14 lawmakers asked President Barack Obama on Wednesday to delay a decision on the pipeline and investigate alleged conflicts of interest over the project.
But Kerry, who is known for his work on climate change legislation, was not among them. His statement on the pipeline came after after Friends of the Earth urged pipeline opponents to call Kerry's office and demand he take action.
"Senator Kerry prides himself on being a climate champion, yet he's been silent on the oily influence scandal surrounding the State Department's review of the Keystone XL tar sands oil pipeline, citing a busy schedule as the reason," the group said on its website.
Kerry, one of 12 U.S. lawmakers service on the special deficit-reduction "super-committee" trying to reach a long-term budget deal by Nov. 23, defended his environmental record.
"I think that the environmental focus I brought to this Committee, and the environmental bonafides of President Obama and Secretary (Hillary) Clinton, should underscore that we all approach this issue with appropriate seriousness and sensitivity," he said in the statement.