LOS ANGELES — Los Angeles could lose and win its Olympics gamble, ending up with the 2028 Games it never sought and the costly prospect of retooling its multibillion-dollar plans for more than a decade into the future.

In an atmosphere of uncertainty, International Olympic Committee leaders began three days of meetings and site visits Wednesday to weigh LA’s plans for the 2024 Games in its showdown with rival Paris. A decision is scheduled for September.

The two cities are the only remaining bidders after a string of embarrassing withdrawals by Rome, Hamburg, Germany, and Budapest, Hungary. Looking to avoid another messy competition, the International Olympic Committee has made an unusual proposal to award the next two Olympics, 2024 and 2028, one to each city.

LA organizers have publicly winced at the 2028 option — as with Paris, they say they are bidding only for 2024. The consolation prize would not only be a disappointment in LA, it would leave the city with challenges from maintaining public interest to recasting deals for stadiums, arenas and housing that have been in the works for months and even years.

Remaking LA’s plan for 2028 “would take an awesome amount of work because all of the conversations, all of the negotiations, all the plans, have been built around 2024,” said Gary Toebben, who heads the Los Angeles Area Chamber of Commerce.