The 2020 Summer Olympic budget remains unchanged at $12.6 billion after the increase in some areas were offset by the reduction in others, with Games organizers acknowledging on Friday that more work was needed to curb spending.

Organizers have been working to cut expenses since a study warned they could balloon to four times estimate made during the bidding process, while the International Olympic Committee (IOC) wants Tokyo to set a good example for future host cities.

However, the third version of the budget announced on Friday was equal to the projection issued last year, after the management organizes to reduce it from $14 billion outlay unveiled two years ago.

"There is still a lot of work to be done to control expenditure," Tokyo 2020 CEO Toshiro Muto said in the statement.

Organizers said requirement was becoming clearer with less than 600 days to go until the event, prompting them to bump up.

"But the corporation of the IOC, Tokyo 2020 will continue to make best efforts to maximize revenues, contain cost and keep its budget within $ 5.6 billion," he said.

Overall the budget of the Tokyo Metropolitan Government accounts for $5.6 billion and the government $1.4 billion, unchanged from the last year.