Democratic presidential candidate John Kerry (search) calls America "a country of optimists" and outlines his plan to make the nation "stronger at home" and "respected in the world" in a television ad unveiled Tuesday.

The 30-second commercial is the first in a new round of advertising meant to explain Kerry's proposals on the economy, health care and national security.

Kerry will spend $18 million in June, a heavy amount for five months before the election, to run issue-focused commercials in media markets in 20 states — including GOP-leaning Virginia for the first time — and nationally on cable networks.

"We're a country of the future. We're a country of optimists. We're the can-do people," Kerry says in the new ad, which is filled with pictures of American flags, children, veterans and the candidate on the campaign trail.

The ad says that for Kerry "a stronger America begins at home" and highlights his domestic plans to create jobs, lower health care costs and make the nation less reliant on Middle Eastern oil. The ad also promises "a strong military and strong alliances to defeat terror."

On Wednesday, the commercial will replace 60-second biographical ads, which survey his life from his birth to his military service to his Senate career, that have been running in 19 states since early May. The campaign won't run the new ad just yet in Virginia. A biographical spot will air instead.

Kerry strategists believe the bio ads helped Kerry's image in the wake of ads by President Bush that labeled the Democrat a flip-flopping liberal.

Mark Mellman, Kerry's pollster, cited independent polls, such as the National Annenberg Election Survey from the University of Pennsylvania last week. It showed that 44 percent of people in battleground states view Kerry favorably, up from early May when 39 percent had a favorable impression.