RIO DE JANEIRO, Brazil (AFP) — Presidents from France and Hungary, Italy’s prime minister and the US secretary of state headed for Rio on Thursday to step up their countries’ bids for the 2024 Olympics.

Budapest, Los Angeles, Paris and Rome are in contention to stage the 2024 Games and the Rio Games will be a key campaign stage ahead of the International Olympic Committee vote in September next year.

With the International Olympic Committee plunged into the Russian doping crisis, lobbying will be more difficult though crucial as access to the IOC is more restricted.

“It’s my responsibility to be here, in Rio, to meet the maximum number of representatives of the Olympic movement and to convince them that Paris is the best choice and France the best destination,” said France’s President Francois Hollande as he stepped off a jet emblazoned with the Paris 2024 logo on Thursday.

Hollande will be jostling for attention with Italy’s Prime Minister Matteo Renzi, US Secretary of State John Kerry and Hungary’s President Janos Ader at the Rio opening ceremony on Friday.

Renzi was due to visit a favella – as Brazil’s slums are known – in Salvador in the northern state of Bahia before opening the Casa Italia in Rio – the centre for Italian athletes, officials and fans during the Games.

In the absence of Rome’s new mayor Virginia Raggi, who is not going to Rio and has expressed doubts about Rome’s bid in the past, Renzi is going to be busy in Brazil.

On Friday he is going to the opening ceremony and will meet International Olympic Committee president Thomas Bach on Saturday.

Kerry will head the US delegation at the Games and is due to arrive in Rio on Friday, in time to attend the opening ceremony after a visit to Argentina.

He will be accompanied by several officials and nine-time Olympic gold-medalist swimmer Mark Spitz.

Also present will be Gene Sykes, the CEO of the Los Angeles bid for the 2024 Games.

“We want to say and show that we are very enthusiastic to be the host of the 2024 Games,” said Sykes.

“We will do whatever we can to be partners of the IOC.

“Rio 2016 is a fundamental part of our listening and learning phase.”

Hungary’s Prime Minister Viktor Orban will be pressing the Budapest bid when he comes to Rio for the Games closing ceremony.

“As a committed sports fan the Hungarian prime minister will have the opportunity during his visit to talk to the Olympic family about the reasons why Budapest is honoured and excited to be bidding for the right to host the 2024 Games,” said a Budapest spokesman.

There is no clear favourite though Paris and Los Angeles are considered the frontrunners.

French IOC member Tony Estanguet said Rio was a chance to “take the temperature of the IOC’s expectations” for 2024.

The IOC vote will be at a meeting in Lima in September next year.