The construction site for the National Stadium, venue for the upcoming Tokyo 2020 Olympics

The International Olympic Committee (IOC) insisted Friday the showpiece venue for the Tokyo 2020 Summer Games would be completed on schedule after a disastrous rollout of the initial plans.

Japanese Prime Minister Shinzo Abe tore up the blueprints for the new national stadium two years ago amid public anger over its $2 billion yen price tag in an embarrassing setback for local organisers.

That decision deprived the 2019 Rugby World Cup -- also hosted by Japan -- of its main venue, but the IOC dismissed fears of the sort of rush job seen at previous Games.

"We visited the national stadium for the first time since its construction commenced," Tokyo 2020 coordination commission chairman John Coates told reporters at the end of a three-day visit.

"We were very impressed to see it's well and truly coming out of the ground, is on budget and we were absolutely assured it will meet the completion target of November 2019 which is so important for us."

Coates underlined the progress made since the IOC ordered Tokyo organisers to keep costs below $20 billion, pointing to a saving of $2.2 billion on a revised construction budget.

"That's not to say we are not continuing to work with our partners to identify further savings," said the Australian, who confirmed the IOC's contribution to the budget was $1.5 billion.

"Those savings for taxpayers are very high among our priorities."

Tokyo governor Yuriko Koike last year ordered a review of the budget that recommended revised plans to reduce costs projected to balloon to more than $25 billion -- four times the initial estimates when Tokyo won the 2020 hosting rights.

- Slashed costs -

Local organisers have since slashed costs to around $13 billion, Coates noted, adding: "The framework is there, the budget is there -- we just now have to work together to deliver."

The IOC are under increasing pressure to rein in sky-rocketing budgets and have pledged to make changes to the Olympic bidding process following the withdrawal of Budapest from the race to host the 2024 Games, leaving just Paris and Los Angeles in the running.

Rome, Hamburg and Boston all previously pulled the plug on their bids for the 2024 Summer Games, citing costs.

In addition to boasting "a record 48.8 percent female participation" in Olympic sports, Coates said that the 2020 host nation's baseball and softball teams would play games in disaster-hit Fukushima.

"The first baseball game and the first softball game involving Japan will be held in Fukushima," he said following lengthy discussions on how to include the region, ravaged by a nuclear meltdown following the 2011 tsunami that devastated north-east Japan.

Tokyo organising chief Yoshiro Mori predicted the 2020 Olympics would be "revolutionary" after the inclusion of 15 new events, including new sports such as three-on-three basketball and freestyle BMX with more appeal to a younger audience.

"We have had very positive discussions this week," he said. "I'm almost embarrassed by all the praise we have received from the IOC commission."