WASHINGTON (Reuters) - Outgoing U.S. Secretary of State Hillary Clinton on Tuesday cast doubt on speculation she might run for the White House in 2016.

In an interview taped for National Public Radio, Clinton was asked what questions she needs to answer for herself as she decides whether to run for president.

"I'm not even posing those questions. I am really looking forward to stepping off the fast track that I've been on. I've been out of politics as Secretary of State. I don't see myself getting back into politics," she said, according to an excerpt of the interview.

Whether this is her last word on the subject is unknown. She will face strong pressure from Democrats to join the field of contenders. Clinton will step down this week, following Senate confirmation Tuesday of Massachusetts Democratic Senator John Kerry as her successor.

Those close to Clinton are eager for her to announce a 2016 run, so much so that a group has already formed a new super PAC and registered with the Federal Election Commission on Friday, called "Ready for Hillary."

In 2008, she lost to President Barack Obama in a bitter Democratic primary campaign to be the party nominee for the White House.

Although Clinton, 65, did not categorically rule out another presidential run, in a separate NBC interview she said that she was healthy enough to wage a campaign.

"I have no doubt that I am healthy enough and my stamina is great enough and I'll be fully recovered to do whatever I choose to do," Clinton told "Andrea Mitchell Reports" in an interview that aired on Tuesday.

Clinton was hospitalized in December after doctors found a blood clot stemming from a concussion she suffered previously.

She intends to do more public speaking and writing, and work alongside her husband, former President Bill Clinton, and daughter Chelsea on "mutual foundation interests," she said in the NPR interview.

"I want to be involved in philanthropy, advocacy, working on issues - like women and girls - that I care deeply about," Clinton said.

(Reporting by Margaret Chadbourn; Editing by Cynthia Osterman)