The International Olympic Committee (IOC) has laid the blame squarely on Boston for its aborted attempt to host the 2024 Summer Olympics, saying the city had failed to deliver on its promises.

Boston was picked by the United States Olympic Committee to be the country’s candidate for the 2024 Games but USOC rescinded its bid in a spectacular U-turn on Monday after the city’s mayor said taxpayers could not afford to host the event.

The move was a blow to that campaign and came after four out of six cities withdrew from the 2022 Winter Games race, leaving China’s Beijing and Kazakhstan’s Almaty as the only bidders.

“What we could see in a nutshell, what happened there is that Boston did not deliver on promises they made to the USOC when they were selected,” IOC President Thomas Bach told reporters in Kuala Lumpur on Wednesday.

“Therefore we can understand the decision by USOC and we are looking forward to an American bid with another city,” Bach said, adding that Boston did not appear to have a clear strategy.

“I gave up following it. It was pretty confusing. Every day, there was a new project coming from Boston or new people and new ideas. I really gave up following it in detail.”

While the surprise withdrawal of Boston was met with relief by Massachusetts officials, who had faced an active opposition campaign that fought the idea of hosting the Games, forecast to cost more than $8.6 billion, it piled pressure on USOC.

Bach said the American Olympic body, which had selected Boston over Los Angeles, Washington and San Francisco in January, had “committed” to submitting a bid for the 2024 Games and he was expecting them to deliver.

“We are not concerned at all. For us the situation has not changed. We had a commitment from USOC for an Olympic candidature for 2024,” said Bach, who is in the Malaysian capital to attend an Executive Board meeting and IOC Session.

“We have this commitment and we are sure that USOC will deliver on this commitment, and that we will have on Sept. 15 a bid from the United States. I have no reason to doubt this commitment by USOC.”

Los Angeles, which has twice hosted the Olympics, has expressed interest in stepping in but any U.S. bid will need to rush to meet the September deadline for applications.

So far Rome, Paris, Budapest and Germany’s Hamburg have declared their candidacies. The IOC will elect the host in 2017.