TEHERAN - For Mr Amir Moghtader, the waiting has become a torment. Uncertainty is the cause, but as the clock ticks down, he still hopes there can be a nuclear deal for Iran.
"I don't know what the solution is, but the government should find it and it should benefit both sides," he said.
The 52-year-old taxi driver, like all Iranians, has become accustomed to waiting. But while diplomats bargain over terms that could end a 13-year crisis over the country's nuclear programme, minds are filled with doubt about the eventual outcome.
A third day of talks in Vienna began focused on the role of international monitors, as reports emerged of a new letter from United States President Barack Obama to Iranian officials.
A breakthrough seemed to have been made in the meeting yesterday, as a senior US official said, on condition of anonymity, that Iran and major powers had reached a system that will allow the United Nations' atomic watchdog to inspect suspect sites.
But details were not immediately available, and it was not clear if Mr Obama's letter had contributed to the agreement.
Amid the diplomacy, the Iranian Students' News Agency reported that Iran's Supreme Leader Ayatollah Khamenei had received a fifth letter from Mr Obama earlier this month, citing senior lawmaker Mehrdad Bazarpash, who declined to say what it contained.
Despite agreeing on the outlines of an agreement on April 2, the final talks between Iran and six powers led by the US on turning it into a binding accord have hit difficulties.
A deal would lift sanctions, paving the way for foreign investment to flow back, in exchange for curbs on Iran's nuclear activities.
Just four days before the current talks started, Mr Khamenei ruled out military inspections.
While Mr Moghtader may not work in oil or finance, the two biggest industries affected by Western sanctions on Iran, the economic fallout has hit him all the same.
"If I have to buy a spare part for my car, I have to pay the equivalent price in dollars, but what I get from my customers is rials," he said, alluding to inflation that has seen Iran's currency shed two-thirds of its value since 2011, when the nuclear crisis began to engulf the economy.
For Mr Ahmad Asgari, an oil and gas consultant, the final outcome is pivotal.
Having once employed 100 people, only 20 remain on the payroll at the Association of Petroleum Industry Engineering and Construction Companies, where he is managing director.
"We cannot endure this situation anymore. I have spent all my savings," he said.
The economic divide in Iran has widened as sanctions have hit home.
Mr Jahangir Raafat, an oncologist, is one of the more fortunate ones, riding out hard times as he always has a full waiting room of 30 patients.
"Everybody wants the sanctions removed, things would get better," he said. "But we can manage if there is no deal."
AGENCE FRANCE-PRESSE, BLOOMBERG