Bill and Hillary Clinton are out with a statement endorsing Democratic nominee Bill de Blasio for New York mayor.

The endorsement comes two days after de Blasio's potential runoff opponent, 2009 nominee Bill Thompson, conceded the race.

"Bill de Blasio has been a friend to both President Clinton and Secretary Clinton for many years," said spokesmen for the Clintons. "They were proud to see him run a thoughtful, creative campaign about the issues, and they are behind him as he moves on to the general election as the Democratic nominee."

The Clintons had personal ties to several candidates in the race, including former congressman Anthony Weiner, whose wife works for Hillary Clinton. De Blasio was Hillary Clinton's campaign manager during her 2000 Senate campaign.

De Blasio faces Republican former Metropolitan Transportation Authority chairman Joe Lhota in the general election and is a heavy favorite.

Philip Rucker contributed to this report.