Nuclear talks between Iran and the five permanent memers of the UN Security Council are set to begin in Geneva.
The key issue on the negotiation table is Iran's uranium enrichment programme.
The meeting, which starts on Tuesday, follows a rare personal phone call between the presidents of Iran and the United States. Iran's delegation wants international sanctions to be lifted, while the international community wants assurance that Iran will not be pursuing nuclear weapons.
Al Jazeera's diplomatic editor James Bays reports from Geneva.