WASHINGTON — The silence between Barack Obama and Bill Clinton has been broken, with the Democratic White House hopeful today asking the former president to campaign for him during their first conversation since the heated primary.

Bill Clinton was often Obama's harshest Democratic critic, trying to bring down the Illinois senator as his candidacy surpassed former first lady Hillary Rodham Clinton's. While Hillary Clinton has begun to help Obama by encouraging her supporters to back his campaign, a chill remained between the last Democratic president and the man running to be the next one.

Obama spokesman Bill Burton said they had a "terrific conversation" and that Obama is honored to have the former president's support.

"He has always believed that Bill Clinton is one of this nation's great leaders and most brilliant minds, and looks forward to seeing him on the campaign trail and receiving his counsel in the months to come," Burton said.

Clinton spokesman Matt McKenna said the former president renewed his offer — expressed in a one-sentence statement last week — to do whatever he can to ensure Obama wins the presidency.

"President Clinton continues to be impressed by Senator Obama and the campaign he has run, and looks forward to campaigning for and with him in the months to come," McKenna said. "The president believes that Senator Obama has been a great inspiration for millions of people around the country and he knows that he will bring the change America needs as our next president."

Obama spokesman Robert Gibbs said the senator called Clinton after Obama landed in Missouri Monday morning, and they spoke for about 20 minutes. Gibbs said Obama asked Clinton to campaign with him and separately.

"I believe he's excited to do it," Gibbs told reporters traveling with Obama.