"I've got good news for you. And that is that this nation is going to come roaring back," Romney said to enthusiastic applause at a campaign stop in Mooresville.
Accusing President Barack Obama of making the US "more and more like Europe," Romney warned that the current course was giving the United States "chronic high unemployment, low wage growth and fiscal calamity right at the door."
"I don't want to be like Europe, I want to be like America," Romney said.
The rally at a NASCAR training facility here in the heart of stock car racing country came a day after Romney introduced his vice presidential running mate, a Wisconsin congressman known for advocating deep cuts in social spending to bring US debt and deficits under control.
The two went on a tear through Virginia on Saturday and were continuing their bus tour through North Carolina, electrifying large crowds who said they were thrilled to see Ryan on the ticket because it assured voters that the Republicans would deliver fiscal restraint and smaller government to Washington.
"The contrast could not be more clear," Ryan told some 1,700 supporters inside the building, as a swelling crowd of 4,000 waited outside.
"We can either stay on the path that we are on -- a nation in debt, a nation in doubt, a nation in despair, a nation of high unemployment, where we're giving our children a diminished future -- or we can change this thing and get this country back on the right track."
Both candidates lashed Obama for policies that they said have suffocated any substantial economic recovery and stunting job growth in North Carolina, where unemployment is 9.4 percent, well above the national average of 8.3.
Ryan said the current high taxes, health care reform law mandates, and excessive regulation on industry -- the "choking red tape" of the Obama administration, as he put it -- prevent small businesses from creating jobs.
"It's killing us!" a supporter shouted.
Ryan, who chairs the House Budget Committee, was relishing the chance to bring his message of fiscal responsibility, balanced budgets and deficit reduction to voters on the national stage as he and Romney look to frame the election debate around major issues like the role and size of government.
The pair also appeared decidedly relaxed with one another, with Romney, the former governor of Massachusetts and wealthy businessman and investor, gelling with the wonkish policy insider Ryan, 42, who has literally spent half his life in Washington.
At each stop since his first appearance as Romney's VP pick, in Norfolk, Ryan has buffed up Romney's image, which has suffered in recent weeks with Democrats attacking his record as a multimillionaire investor and painting him as unconcerned about everyday Americans.
In Mooresville, the pair jumped out of their campaign bus to address the overflow crowd, and Ryan quickly extolled his political partner.
Romney is "a family man, a man with a bedrock of principles, a man with a moral compass, with a vision for this country and the proven experience to put that vision into practice and re-ignite the American dream," he said.
North Carolina native Judy Britton, a retired entrepreneur and former school teacher, said a "charismatic" Ryan, with his boundless energy and intellectual heft, rounds out a winning pair.
"I think they make a great team," she told AFP.
"I'm really concerned about the way the country is going, and I feel like we've got a ticket that can turn it around," she added.
"We need leadership that's willing to make some bold choices," she added, referring to the looming debate over taxes, spending cuts, and entitlement programs for retirees and the poor such as Medicare and Medicaid.
Romney and Ryan travel to Ryan's home state of Wisconsin later Sunday but will then part ways, with Romney traveling solo to the biggest battleground states of all, Florida and Ohio, and his running mate campaigning in Iowa.
