Biden immediately started lashing out at the Republican Presidential candidate John McCain for being out of touch with middle and lower class.

"We can't afford four more years of a government that does nothing while they watch the housing market collapse," said Biden, referring to reports saying the Arizona Senator admitted he was unsure how many properties he owned.

US Democratic presidential candidate Barack Obama, for the first time, introduced his selected running mate, Senator Joe Biden, at a rally in Illinois, on August 23, 2008.[Xinhua]

"Ladies and gentlemen, that is not a worry John McCain has to worry about. It's a pretty hard experience. He'll have to figure out which of the seven kitchen tables to sit at."

Obama's campaign officially announced early on Saturday through emails and text messages that he has selected Biden as his running mate, which was not a surprise since speculations have been on for weeks that Biden would be the final choice.

Hillary Rodham Clinton, who was named by most supports as the vice president candidate, said in a statement earlier the day that she had never formally vetted for the No. 2 position.

"Senator Biden will be a purposeful and dynamic vice president who will help Sen. Obama both win the presidency and govern this great country," she said.

(Xinhua News Agency August 25, 2008)