Tokyo Olympic organizing committee President Yoshiro Mori said Monday the 2020 host city must start producing with no time to waste, exactly three years to the opening of the games.

"Three years from today, July 24, will be the opening ceremony," Mori said during his address to the executive board of the organizing committee. "Not exactly the most commemorative day, but I think it means something for this board to be meeting on this particular day."

"I said (at the start of the International Olympic Committee's Coordination Commission in June) that this year, any reply from Tokyo to the IOC must say by when and how; considering or trying something is no longer good enough."

"Now comes the hard part."

Tokyo's second Summer Games, to be held July 24-Aug. 9, 2020, will feature a record 33 sports and 339 events with an overall budget of 1.39 trillion yen ($12.5 billion), which will also cover the Paralympics.

On Monday, Tokyo, which last hosted the games in 1964, kicked off the three-year countdown with a lights and music show at the metropolitan government building, where the nationwide tour of the Olympic and Paralympic flags was officially launched with Olympians and Paralympians past and present named as ambassadors.

Organizers also unveiled a 2020 rendition of the "Tokyo Gorin Ondo," which was the theme song for the 1964 Games. "Tokyo Gorin Ondo," a Japanese summer folk dance tune, was one of the bestselling songs of its time.

Tokyo Gov. Yuriko Koike said the Tokyo Games are still about aid and recovery, pointing to the intense rainstorms and flooding this summer that have forced households to evacuate in areas like Tohoku in northeastern Japan and Kyushu in the southwest.

"We're only three years away now from the Tokyo Olympics and Paralympics," Koike said. "The Tokyo Games is an Olympics about recovery. It's ironic that we are facing more disasters ahead of an Olympics like Tokyo's, but we want to make these games a success and aid in the relief of the disaster areas."

Since being awarded the hosting rights four years ago, Tokyo certainly has had it challenges, from a plagiarism controversy surrounding the official emblem to an outlandish price tag on the main Olympic stadium and to soaring overall costs of the games.

Tokyo initially sold itself on being a compact Olympics, but has turned out to be anything but that, involving eight other prefectures.

Organizers have yet to outline how they will replace a transport plan that has been scrapped by the delayed decision to relocate the Tsukiji fish market to another part of town, and how they will deal with the heat during the height of summer.

Mori said Tokyo has to act with a continued sense of urgency.

"The media have had some strong words today marking three years to the Olympics, on transport and considering how hot it is on this day, how we need to deal with the extreme heat," the former Japanese prime minister said.

"Our work is cut out for us. People say we need to do this and that like put cooling devices on the roads, but on the other hand they say we have to stop spending."

"So we have to strike the right balance between stepping on the pedal and slamming the brakes when and where needed, which will not be easy," he said.

Japanese athletes gunning for Tokyo are expecting the next three years to fly by.

"I think it'll go by incredibly quickly because after the nationals next year, it's pretty much right there," said female swimmer Rikako Ikee, who is competing at the ongoing world championships in Budapest.

"Looking ahead to Tokyo, I want to make each and every meet count."