BOSTON (AP) — Barack Obama's re-election campaign kept up pressure against Republican rival Mitt Romney on two fronts Friday, launching a new ad defending the president's record on Medicare while challenging Romney to release at least five years of tax returns.

The TV advertisement, accusing Romney and running mate Paul Ryan of undermining the health care program critical to millions of seniors, came as Romney continued raise money in non-battleground states. That remains a top priority, even with the election less than 12 weeks away and Obama making extended visits to toss-up states such as Iowa and Ohio.

Obama campaign manager Jim Messina said the president's camp would seek no further disclosures if Romney would release five years of his individual tax returns. The Romney campaign, which often says there will be no end to Democrats' demands for tax records, rejected the offer.