Tokyo and other upcoming Olympic host cities must make an "unwavering commitment" to achieving a successful Games, the International Olympic Committee (IOC) urged on Monday, as cost overruns plague the run-up to Tokyo's 2020 event.

In a video message to a debriefing in the Japanese capital on the Rio Olympics, IOC chief Thomas Bach hailed them as "marvellous games" held in a "marvellous city."

"Organising the Olympic Games is an intensive process that requires creativity, discipline and collaboration with many people and stakeholders," he said.

"Most importantly, it requires unwavering commitment."

The three-day debriefing has drawn senior officials from the IOC and Olympic organisers from Rio and Tokyo as well as the hosts of the Winter Games in 2018, South Korea's Pyeongchang, and 2022, which are being held in Beijing.

Among others taking part were Tokyo governor Yuriko Koike and Rio de Janeiro mayor Eduardo Paes.

Bach has previously praised the Rio Games, which were generally seen as successful despite Brazil's political and economic crisis and security and attendance problems.

Koike, now spearheading a cost-cutting fight, told the meeting that she wants to learn from Rio, where she said materials for some facilities were recycled to build a school.

Koike said that Tokyo wants to introduce a spirit of avoiding wastefulness by "drawing on efforts in Rio as well as the IOC's long experience, wisdom and knowledge".

The debriefing came as negotiations over options for moving some Tokyo 2020 venues intensified.

Tokyo is eyeing ways to save money after warnings that costs could hit an eye-watering $30 billion -- four times the initial estimate and almost triple that of the 2012 London Olympics.

Options include relocating venues for canoeing and rowing as well as volleyball, and scaling back plans for a new swimming venue.

Koike and Bach agreed last month to set up a working group to try to control costs.

IOC official Christophe Dubi said earlier this month the rowing and canoeing could take place in Miyagi prefecture, 250 miles (400 kilometres) north of Tokyo, and the volleyball in Yokohama south of the capital, following recommendations from a Koike-appointed panel of experts.

But Tokyo officials have faced resistance from 2020 organisers, who argue that moving some events to Miyagi, which was badly hit by Japan's 2011 tsunami disaster, could actually cost more because the region lacks the proper infrastructure.

Dubi said Sunday in Tokyo that detailed options for moving some Tokyo venues would be presented at a meeting involving the IOC, Tokyo 2020 organisers, the Tokyo metropolitan government and the Japanese government on Tuesday.

Source: AFP