WASHINGTON, Feb 2 (Reuters) - U.S. President Barack Obama still wants to hear from other federal agencies before deciding whether to accept the State Department's finding that the Keystone XL pipeline would have no major impact on climate change, his top aide said on Sunday.

White House Chief of Staff Denis McDonough said Obama would decide once the Environmental Protection Agency, Energy Department and other federal experts offer their assessments of the State Department review, as well as their own analysis.

But McDonough offered no word how soon Obama may rule.

Pressure on Obama to approve the project mounted on Friday with the release of the State Department report, which concluded the pipeline's impact on climate change would not be significant.

Backers argue that the State Department's findings should clear the way for prompt approval of a bid by TransCanada Corp to build the $5.4 billion project, which would transport crude from Alberta's oil sands to refineries on the U.S. Gulf Coast.

Appearing on NBC's "Meet the Press" and CBS's "Face the Nation," McDonough said the president's top concern remains the environment, not election-year politics.

The State Department report riled environmentalists, many of whom are part of Obama's liberal base. Yet it delighted the project's backers who include congressional Republicans as well as some of Obama's Democrats up for reelection this November.

McDonough called the State Department review "one of many important inputs into the process."

"What the president's role is now is to protect this process from politics, let the experts, the expert agencies and the cabinet secretaries make their assessments both of the study that was put in on Friday as well as its impact on the national interest," McDonough said.

"So we'll resolve that over the coming period of time," McDonough said.

Louisiana Governor Bobby Jindal, a Republican and an outspoken proponent of the project, told CNN's "State of the Union" on Sunday there was no reason for Obama to oppose the project "unless it's just purely ideological."

"This goes to an absolutely critical issue, cheap, affordable domestic energy (which) is an absolute critical component for us reviving our manufacturing-based economy," Jindal said.

"This is a no-brainer," the governor said.