Tokyo Tower and the Yoyogi Building shone in the Japanese capital, while other buildings stretching from the Goryokaku Tower in the northern Hokkaido region to Fukuoka Tower in the south were also lit-up in the colours of the Olympics rings.
Tokyo Skytree, the tallest tower in the world, was also illuminated following a countdown event held halfway up the 634-metre structure.
At the ceremony, commemorative lanterns were lit by school children, athletes and dignitaries, including Tokyo 2020 President Yoshiro Mori and Governor of Tokyo, Yuriko Koike.
"We want to send a message to the world that Tokyo is a host city. Also, the success of the Tokyo Games depends on reconstruction (in Fukushima)," said Koike.
Eric Garcetti, the mayor of 2028 host city Los Angeles, was also in attendance as a guest of Koike.
"We share a common geography of the Pacific and we share a common dream of the future between Los Angeles and Tokyo," Garcetti said.
"We come here with a delegation from Los Angeles today to pay our respects to the wonderful organising efforts of Tokyo 2020."
The presentation stage was decorated with 731 paper lanterns, each representing the days remaining until the Games' opening ceremony. Attendees wrote their wishes for the 2020 Games on the lanterns.
Sport climber Miho Nonaka, who will hope to be competing in the sport's Olympic debut in Tokyo, said she wrote 'even higher' on her lantern.
"I want the (climbing) walls and my goals to be higher, and I want to climb to the highest point," she said.
After the illumination, the athletes joined the assembled children in performing the Olympics' official song 'Tokyo Gorin Ondo 2020.'
The Tokyo Games will start on July 24, 2020 and run until Aug. 9.
(Reporting by Jack Tarrant; Editing by Christian Radnedge)
