Paris Mayor Anne Hidalgo remains cautious about a potential Paris bid for the 2024 Olympics, saying she still needs to be convinced that hosting the games will be worth the effort.

In an interview with French television station BFMTV on Tuesday, Hidalgo expressed her general support for a bid but reiterated her concerns about the costs and the ecological impact of hosting the games in the French capital.

"My heart is rather with sports and the games but at the same time I'm not ready to do any old thing," Hidalgo said. "If we can win, we'll go for them. But there is not a single city that got involved with the games that made economic benefits from them."

The results of a feasibility study on hosting the games will be submitted to Hidalgo on Thursday. She will decide by June whether the French capital should proceed with a bid.

Hidalgo, who has expressed reservations about bidding from the start, revived the issue Tuesday of whether France can bid for both the 2025 World Expo and the 2024 Olympics.

A few months ago, Prime Minister Manuel Valls endorsed the city's candidacy for the world's fair.

Hidalgo said she doesn't think "it's reasonable" for France to bid for both events at the same time. Bids for the 2025 Expo are due in 2016, with a vote in 2018. Initial bids for the Olympics must be submitted to the IOC by September, with the IOC vote in 2017.

"At one point we'll need to choose," Hidalgo said. "We don't have to do it right now, but we'll be forced to make a decision for the games in June at the latest."

French Olympic officials and the sports adviser to French President Francois Hollande, who has voiced support for a Paris bid, have said both events can be pursued at the same time.

Rome and Boston are the only declared bidders so far for 2024. Germany will decide between Berlin and Hamburg as its candidate. Other possible contenders include South Africa; Doha, Qatar; Budapest, Hungary; and Baku, Azerbaijan.

Paris last staged the Olympics in 1924.

"I can only wait to see more on the economic model, the ecological impact and the governance," said Hidalgo, who wants to make Paris a diesel-free city by 2020. "You can't promote a bid with 15 people, each one in his own corner. We need a solid governance, built around the athletes and the mayor."

Paris bid unsuccessfully for the 1992, 2008 and 2012 Olympics. France also failed with a bid from Annecy for the 2018 Winter Games.

Although an opinion poll published Tuesday showed that 73 percent of the French are in favor of a Paris bid, Hidalgo said public support would not be enough.

"I imposed conditions on ethics, on transparency," she said. "If we were to continue toward the games, I don't want it to be at the detriment of all the things I committed myself for the Parisians, in terms of housing and transport."