Tehran, Iran (CNN) -- Criticism covered the French Foreign Minister's Facebook page and an air of disappointment hovered over much of Tehran just hours after word came that Iran and the world powers had failed to reach an agreement on Iran's nuclear program.
"We thought we were going to have good news," said Houman, a 24 year-old Iranian actor who has been following the talks. "We were hopeful both sides were going to reach a compromise. We were disappointed when it didn't happen."
The Sunday blues in Tehran were in stark contrast to the palpable surge of optimism here 48 hours earlier. On Friday, Iran's Foreign Minister Mohammad Javad Zarif said a "framework" for a deal had been agreed to.
When all six foreign ministers representing the P5+1 -- the U.S., UK, France, Russia, China and Germany -- announced plans to fly to Geneva and join the marathon talks, many Iranians felt an agreement on the first stage of a broader deal was near.
"I really thought there was going to be a deal, but all of a sudden it fell apart," said taxi driver Alireza Hashemi.
The talks in Geneva were held behind closed doors with remarkable secrecy. Two U.S. administration officials told CNN that under a potential deal, Iran would halt enriching uranium to 20% -- a key step on the path to a nuclear weapon -- and render unusable most of its existing stockpile of higher enriched uranium.
But rumors and reports swirled about possible divisions among the P5+1 countries -- with some members pushing for Iran to offer more, including a guarantee not to activate its heavy water reactor in Arak.
What ultimately spoiled an agreement remains unclear, but many Iranians took to social media to blame French Foreign Minister Laurent Fabius.
Shortly after arriving in Geneva, Fabius warned against signing a "sucker's deal" with Iran and told a French radio station: "It is necessary to take fully into account Israel's security concerns."
Israeli Prime Minister Benjamin Netanyahu called the proposed agreement a "bad deal for peace," and said: "Iran is not required to take apart even one centrifuge. But the international community is relieving sanctions on Iran for the first time after many years. Iran gets everything that it wanted at this stage and pays nothing."
Suddenly, due to ordinary Iranians' anger with Fabius, it seemed the U.S. government was no longer public enemy number one in Tehran.
"History won't forget your hostility," Omid Mousavi wrote on the French FM's Facebook page. "We hope for Iranian and American pride and Chevrolets instead of Peugeots."
And Mohammad Reza Ghasemi wrote: "I was always respectful of people who come from France. But you have already spoiled it for me. Can you make it clear for us whether you are Foreign Minister of France or Israel?"
Iran's Foreign Minister Mohammad Javad Zarif didn't mention any names but appeared to confirm on his Facebook page that the deal was blocked by a single member of the P5+1.
"The possibility of reaching an agreement with the P5 +1 existed but it was necessary for everyone to be on the same path, and you heard from public remarks from the ministers that one of the delegations had some problems," Zarif wrote on his Facebook page.
Representatives from Iran and the P5+1 are scheduled to meet again in Geneva on November 20 in another attempt to resolve a decade long dispute over Iran's nuclear program.
Despite their disappointment, millions of Iranians will likely tune in again for the outcome, eager for a settlement they hope will ease more than three decades of economic sanctions and political isolation from the West.
"The little wisdom I have tells me there are things happening behind closed doors that we're not aware of," says store clerk Amir Ghassemi. "But we've learned to live with hope."