LONDON, England (AP) — Brazilian organisers are promising full venues at the 2016 Olympics in Rio de Janeiro, vowing to avoid the problem of empty seats that has dogged the London Games.

With just over four years to go to the 2016 Games, organising committee CEO Leonardo Gryner said yesterday that Rio "can do better than London" in making sure that seats are not left vacant.

"This is not an exclusive problem here in London," Gryner said. "We have noticed this is a challenge for organisers but we have a programme called 'Filled Up Stadium' and we have some ideas of what to do to keep the stadia full at all times."

London organisers have faced criticism for the swaths of empty seats at some venues during the first week of the games. The gaps have been blamed mostly on officials from sports governing bodies and national Olympic committees not using their allocations of prime seats — in plain sight of television cameras and photographers.

The situation has angered members of the public who failed to secure tickets in online sales.

"We would be constantly selling seats and we have to give opportunity to people who are in the surrounding area who can easily enter whenever there are empty seats," Gryner said. "We hope to do better than London but we understand it's not an easy challenge."

London organisers have responded by filling empty seats with soldiers and school children and taking back tickets from accredited officials and selling them to the public.

Gruyner said Rio would devise "a more flexible" approach to head off ticketing problems.

"We will be able to have a better result in Rio than London has had so far," Gryner said. "We will also not build huge venues that will be difficult to fill."

On other issues, Rio officials acknowledged they don't have an exact figure for the cost of the games.

Rio Mayor Eduardo Paes, speaking on a video link from Brazil, said some projects are still being finalised. Gryner said Rio should have precise budget numbers next year. The budget for the London Olympics is $14.5 billion.

Rio will host the first Olympics in South America, two years after Brazil stages the 2014 World Cup.

Gryner singled out transportation and accommodation as Rio's main challenges.

The IOC has warned organisers that the deadlines are getting tighter and the workload is increasing.

"Time is an adversary but time is also on our side," Gryner said. "We'll get a few cold sweats but this is normal. We are on time and going according to schedule."

Meanwhile, Rio plans to keep disgraced former FIFA president Joao Havelange's name on the main stadium for the games. The Joao Havelange Olympic Stadium will host the track and field events.

Swiss court documents published last month showed Havelange received millions of dollars in a World Cup kickback scandal in the 1990s. He paid a Swiss court about $550,000 to end a criminal investigation into alleged embezzlement.

Havelange resigned as an IOC member last year before facing a likely suspension from the IOC.

"He is a historical icon in Brazilian sport," Gryner said. "He already paid. He paid accordingly with the court. We in 2016 and I have a lot of pride to be associated with Joao Havelange."