NORFOLK, Va. - Republican Mitt Romney anointed Wisconsin Rep. Paul Ryan, an ardent conservative and devoted budget cutter, as his vice presidential running mate on Saturday, and the two men immediately embarked on a tour of campaign battleground states vowing to defeat President Barack Obama and repair the long-ailing U.S. economy.

America is "a nation facing debt, doubt and despair," and a transformative change in leadership is vital, Ryan declared to a flag-waving crowd in the first moments after Romney introduced him as his partner for the fall campaign.

"Regrettably, President Obama has become part of the problem... and Mitt Romney is the solution," said the seven-term lawmaker, who at 42 is a generation younger than Romney, 65. Ryan is chairman of the House Budget Committee, the chief architect of deeply controversial budget plans and widely viewed by Republican lawmakers as an intellectual leader within the party.

The two Republican ticket mates basked in the cheers of supporters in a made-for-television debut on a ticket hoping to make Obama's first term his last.