John Coates has labelled the Tokyo 2020 Olympic Stadium as "simply magnificent" after the International Olympic Committee (IOC) Coordination Commission visited the venue.
The New National Stadium is set to be completed in the coming days, with an inauguration event on December 21.
The Japan Sport Council say the inauguration event - titled "Hello Our Stadium" - will tie together sport, music and culture.
Eight-time Olympic champion Usain Bolt will be among a series of Olympic and Paralympic athletes participating in a unique relay, dubbed "One Race".
The stadium has been built at a cost of ¥149 billion (£1 billion/$1.3 billion/€1.1 billion).
It will be the focal point of next year's Olympic and Paralympic Games and will hold the Opening and Closing Ceremonies, athletics and football.
The stadium is designed by Kengo Kuma and is the second to be approved after initial plans were scrapped in 2015 by Prime Minister Shinzō Abe due to spiralling costs.
It features a roof with wood collected from all of Japan's 47 prefectures - and Coates gave a glowing assessment.
He reserved particular praise for Japan's former Olympics Minister Toshiaki Endo, who had reassured the IOC of the timescale for the delivery of the stadium after the initial design had been scrapped.
"You explained you were going to build a lesser-sized stadium of 60,000," Coates said.
"You told us the cost and when it will be finished.
"We saw it today and it is simply magnificent.
"I would like to congratulate you on that.
"It will be fully completed next month.
"It is very important for us, with test events coming up in athletics and plans being put in place for the ceremonies.
"You put your neck on the line and we appreciated that."
The New National Stadium is one of the three remaining permanent venues to be completed prior to the Games.
The Ariake Arena will be delivered in December by the Tokyo Metropolitan Government, with the facility set to be the home of volleyball during the Olympic Games.
The Tokyo Aquatics Centre is the final permanent venue, to be completed in February.
Among the recently completed venues is the Oi Hockey Stadium, with construction having concluded in June.
The IOC Coordination Commission visited the venue and the Ariake Tennis Centre, currently hosting a test event.
Coates referenced the Hockey Stadium when revealing two working groups had been established, with one dedicated maximising the legacy of venues.
The Australian added the second would examine transport plans.
"We are focusing on outstanding transport issues and how we can get firm, committed travel times," he said.
"This is particularly important for the athletes to get them to and from the village and venues with confidence during the Games.
"The second working group we have initiated is on how the legacy of these Games can be maximised.
"We went to see the hockey venue, which has an outstanding permanent grandstand there.
"We want to make sure that venue does not just sit there.
"It is a magnificent venue and there are plans with your hockey federation to maximise the venue for ongoing competitions and so on."