Vienna (AsiaNews/Agencies) - Negotiations between Iran and the P5+1 group (the five members of the Security Council - United States, Russia, China, Britain and France - plus Germany) took place this week in Vienna in an atmosphere of cautious optimism.
At the end of the talks in the Austrian capital, Iranian and US officials said that some "progress" had been made, although there is still a lot of work to do to reach an agreement by the deadline of 24 November.
Sources who were present at the talks said that negotiations are a "critical phase", though some experts have doubts about the possibility of an agreement by the deadline.
Any agreement would have historical significance for all parties involved. It would ensure that Iran's nuclear programme is peaceful and civilian in nature in exchange for the removal of all Western sanctions, which have weighted heavily on its economy. In turn, this would end a crisis in international relations that has lasted for decades.
Since Iranian President Hassan Rouhani was elected last year, relations between Iran and the West have improved. The Iranian leader has worked very hard to end to Tehran's isolation.
If successful, the talks would dispel doubts and meet concerns over the nature of Iran's nuclear programme, which some see as a military programme (e.g. Israel).
At present, the parties are still apart, particularly over Iran's uranium enrichment programme.
Nevertheless, US officials say there is still enough time to arrive at a common position, thus meeting the deadline of 24 November.
In the United States, mid-term elections are underway, and the White House is afraid of changes in the balance of power in the Senate, which would jeopardise any future negotiations.
Iran's Deputy Foreign Minister Abbas Araqchi, last week raised the possibility the talks could be extended, and Russian Foreign Minister Sergei Lavrov said on Tuesday that the deadline was not "sacred".
For some analysts, getting a compromise justifying postponing the deadline and give the parties more time would be a positive step.
The main bones of contention are the timing for the end of US and EU sanctions and how far Iran will be allowed to enrich uranium.
Albeit with somewhat different emphasis, the members of the P5+1 group want Tehran to curb significantly its capacity of enriching uranium, keeping only a few hundred active centrifuges, and ensuring that its activities are peaceful. In return, Iran wants the removal of international sanctions that are strangling its economy.
The State of Israel, some political circles in the United States, and radical Iranian lawmakers are opposed to a deal.
At the end of last year, a provisional agreement was reached, followed by the easing of some sanctions in exchange for a brake on nuclear activity. Since then, the issue of uranium enrichment has not been solved.
"Instead of focusing on problems, we discussed solutions as well," said Iranian Foreign Minister Mohammad Javad Zarif at the end of yesterday's meetings.
"Until everything is agreed, nothing is agreed, and you can get 98 percent of the way, and the last 2 percent may kill the entire deal," a senior US official said.