WASHINGTON, Feb. 12 (UPI) -- Former U.S. Vice President Al Gore is the most well-known Democrat who hasn't, and probably won't, endorse either presidential hopeful, it was reported.

Gore is friendly with Sen.. Hillary Clinton, D-N.Y., and Sen. Barack Obama, D-Ill., and has spoken to them both, CNN reported Tuesday. Gore served eight years as vice president with Bill Clinton before seeking the presidency in 2000.

Since Clinton and Sen. John Kerry, D-Mass., the 2004 Democratic presidential nominee, aligned themselves with a candidate, sources told CNN Gore could become the neutral party elder who facilitates any potential deal between Hillary Clinton and Obama.

The 2007 Nobel laureate has said he would want to work with the party's nominee to promote an environmental agenda.

The two other major Democrats who haven't endorsed a candidate -- Senate Majority Leader Harry Reid, D-Nev., and House Speaker Nancy, D-Calif. -- say neither have endorsement plans, CNN reported.