Republican U.S. presidential candidate Mitt Romney and his newly-chosen running mate, Congressman Paul Ryan, will hit the campaign trail Sunday with a bus trip through the eastern state of North Carolina, the first of several of what many consider “must-win” swing states.

After Romney announced his choice for vice president Saturday morning before a throng of supporters in Norfolk, Virginia, which borders North Carolina, the two struck out across the state pushing a policy of fiscal responsibility.

Romney introduced Ryan to start his four-day campaign bus tour. Ryan told the crowd that America is on the wrong track and said – in his words – “Mitt Romney and I will take the right steps, in the right time, to get us back on the right track.”

The 42-year-old Ryan is a 14-year congressman who has the backing of many influential conservatives.

He chairs the House Budget Committee and has been a vocal leader in cutting the deficit by slashing the U.S. budget.

Romney's announcement ended weeks of speculation on who his running mate would be.

In the November general election, Romney will face U.S. President Barack Obama, who is seeking a second term.