Mitt Romney (left) introduced Paul Ryan as a man of "character and values"
US Republican presidential candidate Mitt Romney has named fiscal conservative Paul Ryan as his running mate in November's election.
Mr Ryan, 42, is a congressman for his home state of Wisconsin and House of Representatives budget chairman.
The BBC's North America Editor Mark Mardell says the decision is a bold and ideological choice.
The Obama campaign said Mr Ryan stood for "flawed" economic policies that would repeat "catastrophic" mistakes.
Mr Romney formally unveiled his running mate in a news conference at the retired aircraft carrier USS Wisconsin in Norfolk, Virginia.