Paris is virtually assured of hosting the 2024 Summer Olympics after its only rival Los Angeles announced it would now bid solely for the 2028 Games.

Key points: Paris and LA were the last two bids remaining after others pulled out due to cost concerns

Paris and LA were the last two bids remaining after others pulled out due to cost concerns IOC will hold its official vote next month in Peru

IOC will hold its official vote next month in Peru Deal would make LA a three-time Olympic city

Both cities were competing for the 2024 Games after several other candidates withdrew from contention, and the stage was set for Paris to win its bid when the International Olympic Committee (IOC) confirmed that Los Angeles had agreed to the later date of 2028.

"The IOC welcomes this decision of the Los Angeles Olympic and Paralympic Candidature Committee, and we are pleased to release the Host City contract 2028 in a transparent and timely manner," IOC president Thomas Bach in a statement.

The agreement follows a vote by the IOC in July to seek an unusual deal to award the 2024 and 2028 Games simultaneously.

The IOC, who will hold its official vote next month in Lima, Peru, said it would make contributions to the Los Angeles organising committee worth about $2.2 billion.

Paris and Los Angeles were the last two bids remaining after a tumultuous process that exposed the unwillingness of cities to bear the financial burden of hosting an event that has become synonymous with cost overruns.

The financial burden Rio faced in hosting the Olympics may deter cities from bidding for future Games. ( AP: Eric Gaillard, File )

Paris was seen as the frontrunner for the 2024 Games because it was passed over in a series of earlier Olympic bids and because the French capital will have marked 100 years since the last time it hosted the Games.

An official designation of Paris for the 2024 Games has yet to be announced, but the city's bid committee welcomed the announcement in Los Angeles.

"Paris 2024 is proud to be working together with the IOC and our friends in Los Angeles to reach a positive solution for both cities, the Games and the whole Olympic Movement for 2024 and 2028," committee co-chair Tony Estanguet said in a statement.

LA to become a three-time Olympic host

The deal would make Los Angeles a three-time Olympic city, after hosting the 1932 and 1984 Games.

Los Angeles Mayor Eric Garcetti described the agreement as a "historic day for Los Angeles, for the United States" and the Olympic movement.

Garcetti said Los Angeles was taking "a major step toward bringing the Games back to our city for the first time in a generation".

LA Mayor Eric Garcetti believes the agreement is a victory for the Olympic movement. ( AP: Jean-Christophe Bott, File )

Los Angeles City Council president Herb Wesson called the agreement a "win-win-win scenario".

"Not just through bricks and mortar, but through new opportunities for our communities to watch, play and benefit from sport," Wesson said.

Los Angeles was not even the first American entrant in the contest. Boston withdrew two years ago as public support for its bid collapsed over concerns about use of taxpayer cash.

The US bid switched from the east to the West Coast, as Los Angeles entered the race.

But the same apprehensions that spooked politicians and the local population in Boston soon became evident in Europe where three cities pulled out.

The dual award of the Games relieves the IOC of having to test the global interest in hosting the Summer Olympics for several years until the 2032 Games are up for grabs.

Reuters/AP