Romney's wife keen to have woman VP

Republican Mitt Romney has been quietly narrowing down his options for a White House running mate, but in the midst of a closely watched vice-presidential sweepstakes, his wife hinted she'd like a woman on the ticket.

Asked directly if her husband should nominate a woman as his VP choice, Ann Romney told CBS News in an interview that aired early on Thursday: "We've been looking at that and I'd love that option as well. So you know, there's a lot of people that Mitt is considering right now."

She said she had a few choices "that I really like a lot", but would not be drawn on who they were.

When the candidate, seated next to his wife during the interview, was asked for comment, Romney quipped: "What she said."

Romney is on the wrong side of the gender gap, with polls showing President Barack Obama leading by double digits among women. A female vice-presidential pick could help Romney neutralise the incumbent's advantage among women voters.

The Romneys participated in Wednesday's July Fourth parade in the small town of Wolfeboro, where they were joined by US senator Kelly Ayotte, a New Hampshire native and prospective pick.

Ayotte was also present last month at a New Hampshire farm when Romney kicked off a six-state bus tour, and her appearances - along with those of others such as Senator Marco Rubio of Florida - could be seen as tryouts for the VP slot.

Another woman in the mix is New Mexico governor Susana Martinez, the nation's first Hispanic female governor. She has said she's "not interested" in being vice-president.

Former secretary of state Condoleezza Rice has also been mentioned, although she, too, has said she would not take the job.

Romney and Obama are locked in a brutal battle for the White House, and Ann Romney took issue with the president's strategy against her husband.

"I feel like all he's doing is saying, 'let's kill this guy'," she said of Obama's attacks.

Obama, who has embarked on a bus tour in Ohio to woo voters, has painted former business man and investor Romney as an out-of-touch corporate raider.

Ann insisted: "Mitt's got the answers to turn this country around.

"He's the one that's got to bring back hope for this country."