LONDON  - Japan's women footballers kick off their quest for a rare double on Wednesday as the first action of the 2012 Olympics gets under way. The Asian giants upset the established order of women's football last year after stunning the heavily favoured United States to win the World Cup in Germany on penalties.

The 'Nadeshiko' are now attempting to become only the second side in history to hold World Cup and Olympic titles at the same time in London. But Japan, who face Canada in Coventry in their opening Group F game, will be desperate to make a winning start after a troubled build-up which has included defeats to France and the United States. A 2-0 loss to the French in Paris last week ensured Japan's preparations for the Olympics ended on a downbeat note following an earlier 4-1 thrashing by defending champions the United States in June.

The duel losses have reinforced the concerns aired by former coach Ryohei Suzuki that Japan's women have taken their eye off the ball since landing last year's World Cup, distracted by a new-found fame and celebrity. Japan, who notched a fourth place finish in Beijing, will nevertheless fancy their chances of progressing from a group which also includes Sweden and South Africa, who also play at Coventry on Wednesday.

"Looking back to the Beijing Olympics, we got to the top four but we were the only team that couldn't get a medal," Japan coach Norio Sasaki said. "After Beijing our objective was to get a medal in 2012 and, although we won the world championship last year in Germany, the objective has not changed. We really want to go for the gold medal."

Meanwhile, the United States launch their campaign with a tricky opener against fast-improving France, who they defeated in the semi-finals of last year's World Cup. US head coach Pia Sundhage revealed the Americans had been monitoring France ahead of their game in Glasgow, sending scouts to watch their victory over Japan last week. "We've been able to give enough information to our players so that they can prepare for that game," Sundhage said in a recent conference call, revealing her side were focusing on France's attacking threat.

"Their strength is the attack. When they get comfortable with the ball in the attacking third they are unpredictable so we need to stay tight and our back four with the midfielders need to be compact and control the game by doing some good defending," Sundhage added. Veteran US forward Abby Wambach, who famously scored the extra-time winner to clinch gold in the 2004 Athens Olympic final against Brazil, meanwhile said her team-mates were determined to atone for the disappointment of losing last year's World Cup final to Japan.

"There is no better motivation than losing in my opinion," said Wambach, who missed the Beijing after suffering a broken leg on the eve of the tournament. "We did a lot of really cool things last summer in Germany and we got a lot of people excited about the women's game again and truthfully throughout my career I wasn't sure it was going to happen. I believe this team has something to prove. I know that a lot of us are competitors through and through I mean we're competing when we're playing ping-pong on our team floor. Whatever it is, we want to win and because we got so close and lost in the most dramatic way you can lose a soccer game, a soccer tournament, not to mention the World Cup, adds even more fuel to that fire." In other matches on Wednesday, Great Britain make their Olympic debut against New Zealand in Cardiff while Cameroon face Brazil.