President Barack Obama's re-election team plans to spend $25 million on advertising this month, a dramatic escalation of its media presence in a handful of states that could determine the outcome on Nov. 6.

Campaign adviser David Axelrod announced the new figure Monday. He said the campaign intends to provide a positive message about Obama's candidacy, but will respond to negative ads from Mitt Romney, the all-but-nominated Republican challenger.

In that vein, Obama's campaign released a new ad Monday portraying America as on the rise and urging voters to stick with the president.

In a shift from many of the campaign's earlier ads, the latest commercial focuses entirely on promoting Obama's record and makes no direct attacks on Romney.

Axelrod contrasted their approach to that of former Massachusetts Gov. Romney, who they said has continued a negative strategy he set during the campaign against his Republican rivals.

Still, Axelrod said Obama's team will respond to criticism forcefully, saying he expects Romney and outside groups that support him to continue pounding at the president and his policies. He referred to two groups, one counseled by former George W. Bush strategist Karl Rove and another founded by billionaire oil industry brothers Charles and David Koch, as the "Karl and Koch brothers contract killers over there in super PAC land."

"We will treat every ad that comes from those entities as an ad from Gov. Romney and we will compare our record and our vision with his and we'll let the American people decide," Axelrod told reporters on a conference call.

The $25 million will ramp up the Obama team's advertising spending significantly.

The campaign spent about $2 million last week for an ad critical of Romney that aired in a handful of key states, according to a Republican strategist who monitors ad spending. That, by itself, represented an increase in ad spending by Obama's team. The new figure will increase spending to an average of $6 million a week.

The ad released Monday, with its more uplifting message, underscores the campaign's recognition that Obama can't win a second term simply by attacking his opponent. Obama also needs to make the case that, despite continued economic unease, he has made things better for the American people and is the right steward for the economy going forward.

The commercial credits Obama with pulling the economy back from the brink of recession and saving the U.S. automobile industry. It also highlights what the campaign sees as the president's foreign policy accomplishments, including killing Osama bin Laden and ending the war in Iraq.

In the ad, a narrator says of the U.S. economy: "We're not there yet, it's still too hard for too many. But we're coming back."

The Romney campaign responded swiftly. "Americans know they're not better off than they were four years ago," spokeswoman Amanda Henneberg said. She ticked through areas of the economy where the Romney campaign says Obama has failed, including high gas prices and home foreclosures.

Fresh economic data released last week underscored the economic challenges Obama will have to overcome if he hopes to hold the White House. The economy added just 115,000 jobs in April. While the unemployment rate ticked down to 8.1 percent from 8.2 percent, the decline was largely because more people stopped looking for work. People who are no longer looking for jobs are not counted as unemployed.

The new commercial follows Obama's back-to-back campaign rallies Saturday in Virginia and Ohio, where the president targeted Romney by name as a protector of the rich who will rubber-stamp the agenda of Republicans in Congress. While Obama's team dubbed the rallies as the official launch of the president's campaign, Obama has been in re-election mode for months, headlining campaign fundraisers and holding official White House events in battleground states.

The Obama campaign said the new ad will air in nine politically important states: Virginia, Pennsylvania, Ohio, Nevada, New Hampshire, Iowa, North Carolina, Florida and Colorado.