The I.O.C. is expected to announce the hosts for the Games formally at a meeting in Lima, Peru, on Sept. 13.
From the start, Los Angeles had made clear that while it preferred to have the Olympics in 2024, it would be willing to accommodate the 2028 Games.
Under the agreement, the I.O.C. said it will give at least $1.8 billion to the Los Angeles organizing committee and will make advance payments of $180 million to compensate the local committee’s costs for the extra four years it must work and $160 million for youth sports programs, a payout that typically comes after the Games.
Thomas Bach, the president of the I.O.C., had previously balked at such a perk, saying the Games themselves were a gift, but apparently came around to it.
The Los Angeles City Council and United States Olympic Committee will consider the agreement in August, and if approved, send it on to the I.O.C. for its vote in September.
The agreement is not without risks for Los Angeles.
The cost and logistical estimates Los Angeles prepared in making its bid for the Games — and selling the idea to local officials and voters — were based on the event taking place in seven years. As officials here began contemplating the probability that Los Angeles would get the Games in 2028, they expressed concern about the uncertainties that injected; costs are likely to be higher than they would be in 2024.
Los Angeles’s plan depended on its sprawling system of stadiums and arenas — some left over from the 1984 Olympics, others belonging to major sports teams and university campuses — that in theory would keep construction costs low. The estimated cost is $5.3 billion, though city officials expected the funding to come from private sources and ticket sales.
The United States Olympic Committee withdrew Boston as its official bid city in July 2015 because of intense local opposition, clearing the way for Los Angeles.
There has been minimal opposition in Los Angeles to the Olympics coming — at least as compared with other cities — reflecting, in part, the successful experience in 1984. Yet there was some opposition from a late-emerging group called NOlympics LA. The group denounced the decision.
“This is a complete miscarriage of anything remotely resembling democracy,” the group said. “We insist that the local media acknowledge the lack of transparency and accountability there is in this last-minute, hastily thrown together ‘plan.’ The council, mayor, bid committee, Donald Trump and I.O.C. are all colluding to thrust an unvetted plan onto the second-largest city in America.”
President Trump had said on Twitter in July he was “working hard” to bring the Games to Los Angeles, and he met in the Oval Office with Bach, to pledge his “full support,’’ the White House said in a statement then.
Getting the Games will be a triumph for Paris, which failed in bids for the 1992, 2008 and 2012 Olympics. This time, it presented a streamlined bid and emphasized staging events at postcard venues, such as open-water swimming in the Seine and beach volleyball at the foot of the Eiffel Tower.
“Paris and Los Angeles are two amazing global cities that are united in their support of the Olympic cause and we stand together now to help the Games thrive in 2024 and 2028,’’ the Paris mayor, Anne Hidalgo, said in a statement.
The dual award to Paris and Los Angeles is seen as a chance to stabilize an Olympic movement besieged by staggering costs and declining interest in hosting by cities in democratic nations. Aside from Boston, Rome, Budapest and Hamburg, Germany, withdrew their candidacies for the 2024 Games. By naming two host cities at once, the I.O.C. will not have to worry about cities losing bids for the Summer Olympics and declining to bid again.
In getting the 2024 Olympics, Paris can celebrate the centennial anniversary of the last time it hosted the Summer Games in 1924. By bestowing the Games, the I.O.C. can also pat itself on the back for helping Paris recover from the recent terrorist attacks.
Paris, like Los Angeles, carries some risk in its bid.
An athletes’ village must still be built, at an estimated cost of $2 billion. If there are severe cost overruns in Paris, this could further discourage other cities from bidding on future Games.
On the other hand, Los Angeles had sold itself as better prepared than competitors. Instead of building an athletes’ village, it plans to use existing dorm rooms at U.C.L.A. And, at this point, no permanent arenas need to be built.
The 2028 Games in Los Angeles will inspire a generation of American athletes, bring an infusion of cash to the United States Olympic Committee and could motivate more American companies to become global corporate sponsors for the Olympics in the wake of McDonald’s withdrawal, said Rick Burton a professor of sports management at Syracuse and a former chief marketing officer of the United States Olympic Committee.
“The biggest pro is, L.A. is a winner again,” Burton said in a telephone interview.
At the same time, he said, there could be a change in the city’s political and Olympic leadership by 2028. Arenas may need updating for the latest technology. And it is possible that new construction will be needed if additional sports are added to the Games by then. Also, Burton said, there is no way to predict what the city’s economy or social mood will be in 2028 or whether a severe natural disaster like an earthquake will occur.
By waiting four additional years, “you’re rolling the dice a few more times,” Burton said. “All of that has to be planned for. My guess is, it will be.”