Democratic presidential hopeful Barack Obama has chosen veteran Delaware Senator Joe Biden as his pick for vice president, the campaign confirmed early Saturday in a text message sent to supporters.
The announcement ended weeks of speculation over which of a handful of likely politicians would get the nod. US media broke the story only about three hours before the official message was sent out, a sign of just how closely guarded Obama's campaign had managed to keep the secret.
The Obama-Biden Democratic ticket was to make its first public appearance at a Saturday afternoon rally in Springfield, Illinois, where Obama got his political start in the state house and launched his presidential bid last year, the dpa reported.
"I'm excited about hitting the campaign trail with Joe," Obama said in a brief email to supporters announcing his pick for running mate.
Biden, 65, is a longtime senator from Delaware and chairman of the upper house's Foreign Relations Committee. He is an expert in international relations who travelled to Georgia this month in the middle of the country's conflict with Russia, and will likely appeal to voters sceptical of Obama's foreign affairs credentials.
But Biden will come under fire for some comments made about Obama during his own brief presidential run this year. Biden questioned whether the 47-year-old Illinois senator was experienced enough, arguing the presidency was not "on-the-job training."
McCain reportedly called Biden Saturday morning to congratulate his long-time Senate colleague on being picked, even as his campaign released a ready-made television advertisement that used Biden's own comments critical of Obama.
"There has been no harsher critic of Barack Obama's lack of experience than Joe Biden," Ben Porritt, a spokesman for Republican rival John McCain, said in a statement.
But even for some McCain supporters, the addition of Biden and his foreign policy expertise to the Democratic ticket brought a sense of relief.
"I'm for McCain but I think Obama is going to win because of the Bush-Cheney problem," said Kendall Johnson, 69, a Denver businessman who is disappointed in US President George W Bush. "I want the next president and vice president to be as strong as possible."
The Democrats gather at their party convention in Denver, Colorado, beginning Monday to formally nominate Obama. Biden is slated to speak Wednesday night.
Other Senate colleagues also offered their congratulations, including New York Senator Hillary Clinton, whose own supporters may be disappointed the former first lady was not chosen herself after an epic primary battle with Obama for the party nomination.Clinton, who addresses the convention herself on Tuesday, called Biden an "exceptionally strong, experienced leader and devoted public servant."
Speculation over who would be Obama's running mate had reached a feverish pitch Friday night. Broadcaster CNN even showed live shots of several of the likely candidates' homes in hopes of some sort of clue.
The rumour mill now turns to McCain, who is expected to announce his own running mate on Friday, just days before the Republican Party convention begins on September 1 in St Paul, Minnesota.
Likely candidates for McCain include Mitt Romney, a former Massachusetts governor who came closest to stealing the party nomination from McCain; Minnesota Governor Tim Pawlenty; and former Pennsylvania governor Tom Ridge.