RIO DE JANEIRO, Brazil -- IOC inspectors are sure to deliver a clear message to organizers of the 2016 Rio de Janeiro Olympics when they arrive for a two-day visit: end delays and speed up.

For their part, Rio officials are expected to promise that games' preparations -- after a late start -- are on course. Behind closed doors, they'll try to soothe concerns about a slowdown in landing local sponsorships, worries over hotel accommodation and transportation, and explain recent public protests that have questioned big spending on major sports events like the Olympics.

International Olympic Committee inspectors, headed by former hurdles champion Nawal El Moutawakel, will be at work Sunday and Monday. During the last visit six months ago, IOC executive director Gilbert Felli said: "We don't have any yellow card to send to Rio."

Any such warning this time would be a reminder of the 2004 Olympics in Athens when then IOC President Juan Antonio Samaranch issued his famous "yellow card" reprimand to Greek organizers.

At least two members of the co-ordination commission -- Richard Carrion and former Olympic gold-medal swimmer Alex Popov -- have spoken openly, saying things need to move quicker.

"There are games that are better prepared and games that give us a little more trouble," Carrion said.

These games are still three years away and sure to stay off the radar until Brazil hosts football's World Cup next year, giving local organizers room to manoeuvr.

This is a challenging moment for South America's largest country, which is trying to organize two mega-events and is facing pushback from citizens who question spending so much on sporting events, particularly in a country with vast inequality, high prices and a slowing economy.

Brazil is spending about $13.3 billion of largely public money on the World Cup. Olympic organizers are expected to announce their budgets in a few months, but public spending could be similar to the World Cup -- or higher.

Leo Gryner, chief operating officer of the Rio games, acknowledged in a recent interview with The Associated Press that organizers got a "six to eight month" late start on building venues.

Gryner said that $700 million in public money may be needed to balance the operating budget. This is the budget to run the games themselves and is expected to be as much as $4 billion when it's announced. He said any shortfall was due to inflation, the sluggish economy and a struggle to sell local sponsorships.

Gryner said the capital budget -- a mix of public and private money aimed at building supporting infrastructure for the Olympics -- could be 35 per cent above the $11.6 billion listed in the original bid.

Sebastian Coe, who headed the 2012 London Olympics, is expected to be in Rio later this year to brief local officials about what to expect over the next two years.

"I still instinctively believe Rio will be a really good games," Coe said. "They will be different. There's a different level of expectation. With every Olympics, they always get there. Some are probably a little bit harder. The IOC will privately tell you some of those journeys are a little bit tougher."

Gryner singled out accommodations as a top priority.

"We will have as many rooms as we need," he said.

Soaring hotel prices are already a problem for the World Cup. The Brazilian government and the justice ministry are reportedly looking into reports that some hotels are gouging and have raised rates by 500 per cent.

There are also doubts about Brazil's decrepit airports. The facilities in Sao Paulo and Rio are rated among the hemisphere's worst, which inspectors have surely noticed travelling through the country. Airports could also face problems accommodating a surge in private jets used by many visitors to the World Cup and Olympics.

Another problem area is the Deodoro Olympic Park, one of four core areas for the games. This run-down northern part of the city has long been neglected and will host equestrian events and a half-dozen others.

"It's a renovation of an area that hadn't been getting any attention and lacked sanitation systems for many, many years," Gryner said.

"Now that we have all the construction starting, and the last (place) will be Deodoro," Gryner added. "We have plans to show them (IOC inspectors), and we have the exact starting date, and finishing date for every venue. We can say exactly where we are."

The other core areas for the games include: the Barra area, located in the south and miles away from the city's famous Ipanema and Copacabana beaches; the area around Rio's Maracana stadium near the city centre; and the Copacabana area.

Football will be played in Rio, Sao Paulo, Brasilia, Belo Horizonte and Salvador.

Rio officials are expected to tell IOC officials that grass will be going down later this year on the new golf course, which will mark the return of the sport to the Olympics.

In addition to the pace of preparations, IOC officials may face questions about the following:

-- WADA's suspension of an anti-doping laboratory in Rio. The lab -- the only WADA-accredited facility in Brazil -- can reapply for accreditation, but the revocation is an embarrassment to games officials.

-- The resignation several weeks ago of Marcio Fortes, who headed the public body co-ordinating planning for the games among the local, state and national governments. Fortes, who handed in his resignation to Brazilian President Dilma Rousseff, headed the Olympic Public Authority -- APO -- and complained he had been marginalized in decision making.

Rio Mayor Eduardo Paes has said co-ordination is going well and the position is not needed.

-- The use of the games to upgrade some of the city's transportation infrastructure. The three biggest projects are: a 16-kilometre (9-mile) extension of the city's subway system into the Barra area; adding four high-speed bus lanes; and, renovating a decaying port.

"There is tremendous pressure with the Olympics," Gryner said. "It's a huge project and we have very big ambitions for the transformation of the city of Rio. We are not losing the opportunity of what the Olympics can bring the city."