Negotiators are meeting in Vienna in attempts to reach a deal that curbs Iran's nuclear program in exchange for sanctions relief.

U.S. Undersecretary of State Wendy Sherman, Iranian Deputy Foreign Minister Abbas Araghchi and EU official Helga Schmid began talks Wednesday in a luxury downtown Vienna hotel.

The talks are fine-tuning a framework agreement reached earlier this month. Iran denies any interest in nuclear arms but has agreed to reduce the capacity of programs that could be used to make such weapons. It wants sanctions ended in exchange.

Complicated details on timing and monitoring remain to be ironed out by the June 30 deadline. The foreign ministers of Iran, the United States and five other countries at the table are expected to join in the talks at a later stage.