Biden 'absolutely, positively' Obama's 2012 running mate

US Vice President Joe Biden delivers a public lecture at the Kenyatta International Conference Centre, Nairobi, June 9, 2010. Photo/STEPHEN MUDIARI

US Vice President Joe Biden left no room for doubt as to whether he will be President Barack Obama's 2012 running mate, saying Wednesday he "absolutely, positively" will be on the Democratic ticket.

Asked on NBC television's "Today Show" program whether he would be Obama's running mate again, Biden, 68, was emphatic.

"Absolutely, positively yes. There's never been any question about that," he said.

"The president's made that clear. Hardly anybody has raised that anymore," the veteran former US senator said, dismissing rumours that he might take a pass on a second grueling presidential campaign as little more than Washington "parlor game" talk.

Biden, himself a contender in the 2008 presidential race, found little traction among Democratic voters before dropping out.

He was later tapped by then-senator Barack Obama to be his running mate, and the pair went on to victory in the historic election that saw America elect its first African-American president.