Negotiations in Vienna to revive the nuclear agreement to reduce Iran’s nuclear program in exchange for US sanctions relief have made slow progress in the last week. The current round of talks ended today, and Iran’s negotiators have returned to Tehran to conduct consultations. 

A senior Iranian nuclear negotiator told Iranian reporters that the proposals discussed “require comprehensive review.” The negotiator said that they would coordinate with their European counterparts after the consultations.

The latest talks began Aug. 3 with Iranian, American, Russian and Chinese negotiators plus representatives from the European Union. The original members of the deal, known formally as the Joint Comprehensive Plan of Action (JCPOA), include Iran and the five permanent members of the UN Security Council plus Germany. While negotiators from the European countries are not present, they are being essentially represented by Enrique Mora, chief of staff to High Representative of the EU for Foreign Affairs and Security Policy Josep Borrell.

These current talks include discussions over recommendations made by Borrell during the Doha talks. Mora of the EU is currently acting as mediator between Iran’s Ali Bagheri Kani and Rob Malley from the United States because the two sides are not talking to each other directly. While the nuclear negotiations need Iran and the United States to resolve differences, they are currently holding talks indirectly due to Iranian insistence stemming from the US withdrawal of the deal in 2018.