Pressure is increasing on world powers and Iran to sew up a deal on Iran's nuclear programme after many months of negotiations.
If an agreement is struck, crippling sanctions which have affected everyday life in Iran will be lifted.
BBC Persian heard from ordinary Iranians about what they think will happen in the talks.
The nuclear negotiations affect every Iranian's life. The reason is inflation caused by sanctions. Many families can no longer afford to live the way they used to.
If they don't reach an agreement now while President Rouhani is in office, both sides will face many troubles in the future.
Iran's economy has been crippled since the last set of sanctions on the oil and banking sectors.
I own three factories. Eight years ago they were working at full capacity, now all three are shut.
About 400 workers, technicians and engineers have lost their jobs. There are many people like me who used to have small manufacturing companies in industrial cities.
These days our cemeteries are growing faster and doing better than our industrial cities.
I was following every single minute of the last round of negotiations. If you remember, you could really see the stress on John Kerry's face. It shows Mr Obama needs to find a way to resolve this matter.
However strong the lobbies are on the other side, I believe the US president is determined to make a deal and he can achieve that.
I'm not optimistic. As our leader says we don't trust the US, the UK or the West in general. Now we see that some people in Iran have put their trust in them and think they can move things forward by negotiation, and the [Supreme] leader has agreed to that.
It's happening but personally, I believe the process will fail. It is just a question of when.
I don't think a deal is possible. There are a lot of entrenched groups in Iran like the Basij [volunteer paramilitary force] and most importantly those who are linked to the office of the Supreme Leader.
These groups won't let it happen and people will keep feeling the pressure.
I'm a farmer but I can't sell the rice I produce. It's not fair on our people.
Farnaz, northern Iran
I am a teacher. I'm following negotiations with excitement. But sometimes it feels like it's dragging on and on.
Either way I don't think we will witness any major changes straight away.
Change will take time to achieve. It won't happen the day after an agreement.