WASHINGTON (CNN) - A key Senate Republican Sunday questioned both the president's proposal and strategy to reform Social Security, amounting to perhaps the most public GOP skepticism to date of the White House effort.

"I think that public discussions thus far, without a specific proposal, has created and enhanced a lot of confusion and fear among seniors, wondering if their benefits now are going to be cut," Sen. Olympia Snowe, R-Maine, said on CNN's Inside Politics Sunday.

Snowe is a self-described moderate sitting on the Senate Finance Committee, which will craft any Social Security reform package. Her stance is likely to be crucial for the fate of Bush's plans to overhaul the system with individual privatized accounts that some critics say would cost as much as $2 trillion to $3 trillion to fund.

Though she said she is not opposed to the idea of personal savings accounts, it has to be "part of a larger retirement security picture, as one dimension" and said she worries about eroding basic tenets of the program.

"I'm certainly not going to support diverting $2 trillion from Social Security into creating personal savings accounts," said Snowe.

"The existing program, as it has been developed in the last 70 years, provides a stable monthly income that has prevented seniors, almost 50 percent from falling into poverty. I don't think we want to erode the principles of that system," said Snowe.

Not only was Snowe critical of the White House plan and public relations effort in recent weeks to press the need for reform of Social Security without many details, she also questioned the need for a massive overhaul now.

"There's various scenarios and interpretations about that urgency. I think first we have to get the facts. There are too many interpretations of the facts, and those scenarios could change based on the variables incorporated in those projections," said Snowe.

President Bush now calls Social Security a "crisis" and says he wants to reform the system before it's too late.

Democrats like Sen. Ted Kennedy, D-Mass., say the White House is hyping the extent of the problem in order to promote a GOP principle of moving government programs into the private sector.

Social Security Trustees say the system will begin to put out more money than it takes in in 2018, finally spending itself out in 2042. The Congressional Budget Office projects that won't happen until 2052.

The president himself has been clear his effort to talk about Social Security's problems is to force the hand of reluctant members of Congress.

In speeches, he tries to convince members of Congress the days of being politically wounded by Social Security "scare tactics" are over, that it is possible to tackle the issue now.

He points to his own re-election after a campaign where he talked about reforming Social Security as proof.

Critics such as Kennedy, however, say it is the president himself who is employing "scare tactics" with his frequent insistence that the program is in crisis.

The Maine Republican said she's hearing a lot of concern from senior citizens in her home state worried their benefits will be cut. President Bush has been vague in his proposal so far, but has promised not to cut benefits for those at or near retirement.

"That's an important statement to make, and I think that certainly has to get out there, because I think it is still -- there is a lot of fear among seniors," Snowe told CNN.

"I think we have to look at, you know, many issues. And first of all, we have to reach a consensus on the level of urgency and the magnitude of the problem before we develop a long-term solution," she said.

Snowe, who told CNN the administration had not contacted her about its plans, urged Congress to take a "thoughtful approach" with reform.

"We should not be acting precipitously to undermine the basic tenet of this program, that has worked well for 70 years by providing a defined, guaranteed benefit," said Snowe.

Snowe is a Senate Republican up for re-election in 2006, and comes from a more Democratic leaning "blue" state, which went for John Kerry in 2004.

It also is heavily populated with senior citizens.