WASHINGTON – Denounced by his Republican rival for divisiveness, President Barack Obama on Monday defended the tone of his campaign in a combative election year and insisted it's actually Mitt Romney's ads that are "patently false." But Obama did distance himself from a particularly provocative negative ad by a political group that supports him.

Obama also joined the cascade of criticism from both parties for comments on rape and abortion by a Republican Senate candidate in Missouri, using that new controversy to draw sharp distinctions between his views on women's health issues and those of Republicans.

Obama made a surprise visit to the White House briefing room, at least partly upstaging a joint campaign appearance by Romney and his running mate, Paul Ryan, in New Hampshire. The rally by Romney and Ryan, their first appearance together after a week of vigorous campaigning separately, had been highly anticipated, drawing an enthusiastic crowd and wide media attention.