TOKYO - Tokyo's 2020 Olympic bid leader Tsunekazu Takeda has said that another failure to land the Games would mean a very long wait to host the world's biggest sporting spectacle.

"It's our last chance," Takeda told Reuters on Tuesday. "We'll win. We have to win. With the rotation of the Olympics it will be many years before Tokyo can go for it again.

"For (our generation) it's the last chance," said the Japanese Olympic Committee president, while adding Tokyo was in better shape this time after its failed 2016 bid.

"We have a better bid this time. We have kept the best components and improved all other areas. We have the experience and we're very confident."

Tokyo faces competition from Madrid, who also lost out to Rio de Janeiro in the race for 2016, and Istanbul after Doha and the Azerbaijan capital Baku were dropped last week.

International Olympic Committee (IOC) president Jacques Rogge raised concerns about Japan's power supply following last year's deadly tsunami and resulting nuclear power crisis.

"The Olympics would use only 0.1 percent of Tokyo's total electric capacity," said Takeda after unveiling the bid's latest candidate city emblem.

Japan used to derive around one third of its electricity from nuclear power before the meltdown at a power plant north of Tokyo triggered by the giant tsunami wave.

The government pulled the plug on Japan's 50 reactors with no word yet on when, or if, they plan to restart them.

"The Olympics are in 2020," said Takeda. "The energy-saving measures put in place since the disaster will ensure that power shortages won't be an issue."

The IOC will select the 2020 host city in Buenos Aires in September 2013.