With just two years to go until the opening of the 2020 Tokyo Olympics, supporters all over Japan braved the heat wave and took part in events aimed at bolstering momentum in the run-up to the next Summer Games.

Tokyo Gov. Yuriko Koike and Tokyo organizing committee chief Yoshiro Mori joined athletes at a countdown ceremony in the Japanese capital, where spectators viewed Tokyo Skytree, the world's tallest broadcasting tower, lit up in the Olympic colors.

"I want to continue introducing Tokyo to the world as a host city. It is important to speed up our preparations," Koike told the crowd of hundreds who gathered at the commercial center in the Sumida district.

Los Angeles Mayor Eric Garcetti also joined the stage and praised Tokyo for pulling off "wonderful organizing efforts" toward the 2020 Games, which take place eight years before his city hosts the 2028 edition.

"We share a common geography on the Pacific and we share a common dream of the future between Los Angeles and Tokyo," Garcetti said.

"Tonight in our neighborhood of little Tokyo, we are celebrating the parallel ceremony as well. So from little Tokyo to big Tokyo, we are waving tonight, together."

The stage, resembling a Japanese traditional summer festival, was decorated with 731 paper lanterns, each representing the days remaining until the Opening Ceremony on July 24. Athletes and fans wrote their wishes and goals for the 2020 Games on the lanterns.

Rikako Ikee, who finished fifth in the women's 100-meter butterfly at the Rio de Janeiro Olympics, said she aims to do better with the help of her home crowd in two years' time.

"I want to win a medal together with the Japanese people," the 18-year-old said. "Swimming is an individual sport, but I want people to support me so I can win."

The July 24-Aug. 9 Olympics will feature a record 339 events in 33 sports, including four -- karate, skateboarding, sport climbing and surfing -- that are on the program for the first time, and baseball/softball which returns after being excluded from the last two Summer Games.

Miho Nonaka, who guns for a medal in the maiden sport climbing event, said, "My goal is to go higher -- I want to climb higher, with an even higher objective."

The organizers also put up booths in the outdoor area around the 634-meter tower to give guests a taste of some of the sports played at the Olympics. Children enjoyed shooting hoops and obtained firsthand knowledge from boxing trainers as they hit punching bags.

Tomoko Kobayashi, 35, came all the way from Ibaraki Prefecture, northeast of Tokyo, and took videos of her two children, aged 4 and 7, experiencing boxing.

"We are not huge sport fans as a family, but hosting the Olympics is a totally different experience," Kobayashi said.

"In two years, I think my children will understand more about sports, so I'm looking forward to watching with them as Japanese athletes compete."

In other parts of the country, Olympic medalists joined a 1,000-kilometer citizens' relay connecting cities in northeastern Japan devastated by the 2011 deadly earthquake and tsunami with Tokyo.

About 1,600 people will run or cycle in the relay, which started in the city of Aomori and will finish at Komazawa Olympic Park in the capital on Aug. 7.

"We pledge not to forget the earthquake and hand over the sash to the next runner," said 16-year-old Minori Kitabatake from Hirosaki, Aomori Prefecture, during the opening ceremony.

In the first 1.7-km leg of the relay, Naoko Takahashi, winner of the women's marathon gold medal at the 2000 Sydney Olympics, ran with people of all ages, including a baby in a stroller and a 74-year-old.

"Athletes are training hard for this day two years from now," Takahashi said after she had finished running. "We want to pass on our feelings toward the quake-hit areas and the Tokyo Games."

The deadly heat that Japan has been facing in recent weeks has also reminded officials of their responsibility to prepare effective measures against heatstroke during the 2020 Olympics and Paralympics.

"On the premise that two years from now will also be boiling hot, we will make our best efforts" Shunichi Suzuki, minister in charge of the Olympics, told a press conference.