Updated

President Obama declared Thursday that the health care overhaul upheld last week by the Supreme Court is "here to stay," as he kicked off his first bus tour of the 2012 campaign.

The president, speaking outdoors to a Maumee, Ohio, crowd with haystacks in the background, adamantly defended the law he spent the better part of his first two years in office passing. While Republican opponent Mitt Romney has vowed to repeal the law if elected, the president said the country will not "go back to the days" when insurance companies could deny coverage to the sick.

"The law I passed is here to stay," Obama said. "Now is not the time to spend four more years fighting battles we fought two years ago. Now is the time to move forward."

Romney, though, argues that the economy can't move forward until the health care law is repealed and replaced with something that contains far less regulation.

The Romney campaign was prepared to counter the Obama message Thursday as the president set out on his two-day bus tour across Ohio and Pennsylvania, dispatching surrogates to the same regions on the Obama itinerary.

Obama's 250-mile "Betting on America" bus tour is taking him through several northern Ohio communities where he received strong support in 2008. The tour also will take him into western Pennsylvania, with a stop in Pittsburgh.

In Ohio, Obama touted the auto bailout as well as efforts to challenge China's trade policies. He cited a new unfair trade complaint filed against China with the World Trade Organization. The complaint centers on new Chinese duties on U.S.-made cars, including the Jeep Wrangler, which is made in Toledo.

The president is talking up his economic efforts in battleground states ahead of a key jobs report.

On Friday, the Labor Department will release June's employment report. The stakes are high for a president trying to convince the country that it is not sliding back toward recession -- the May report showed employers adding the fewest number of jobs in a year, resulting in an uptick in the jobless rate to 8.2 percent. In a glimmer of good news, a survey released Thursday by ADP showed businesses in the private sector added 176,000 jobs last month, marking an improvement over May. The Labor Department will offer a more complete picture of June hiring on Friday.

Both Ohio and Pennsylvania have unemployment rates below the national rate. So far, Obama is polling ahead of Romney in most surveys from those two presidential battlegrounds -- he won both states four years ago.

But the Republican presidential candidate will be fighting hard for the territory, recognizing their historical significance. No Republican has won the White House without winning Ohio.

For the Ohio leg of the trip, Romney has dispatched Louisiana Gov. Bobby Jindal and former Minnesota Gov. Tim Pawlenty to visit the regions on Obama's itinerary ahead of the president's arrival.

They will "emphasize the gap between what President Obama said he would accomplish and his lack of results on jobs, health care and the debt," a Romney spokesman told the Cleveland Plain Dealer.

Obama has released new advertising questioning Romney's commitment to keeping jobs in America while pointing to his decision to rescue U.S. automakers, a major employer in Ohio.

Obama travels later in the day Thursday to Sandusky and Parma. The bus tour starts a new phase of Obama's re-election campaign as he takes a more retail-oriented approach before the September convention in Charlotte, N.C. It follows a six-state bus trip by Romney through the Midwest last month that included stops in Ohio and Pennsylvania.

The president's campaign has spent nearly $16 million in television advertising in Ohio through late June, while the Democratic super PAC Priorities USA Action has spent about $2.7 million, according to officials who track ad buys. Romney's campaign has spent about $5 million, but a series of GOP-leaning outside groups have spent another $8 million, helping the Republican blunt Obama's message.

The Associated Press contributed to this report.