Foreign ministers of world powers are joining talks on Iran's nuclear program in a bid to break a deadlock.
Delegates from Iran and 6 nations have been meeting in Vienna since early this month in an effort to reach a comprehensive settlement by a deadline set for July 20th.
But Iran's Deputy Foreign Minister Abbas Araqchi admitted on Saturday the sides remain far apart.
Speaking on state television, he said the negotiators have agreed on 60 percent of the contents of a final deal. But he said there has been little progress on other key issues, such as how deeply Iran must cut back its uranium enrichment activities and the removal of economic sanctions.
US Secretary of State John Kerry and his counterparts from Britain, France and Germany will attend the negotiations from Sunday.
US State Department Deputy Spokesperson Marie Harf said Kerry will assess Iran's willingness to make a set of critical choices at the negotiation table. She said he'll then make recommendations to President Barack Obama about what to do next.
Observers say the negotiations could be extended beyond the deadline.
Jul. 12, 2014 - Updated 23:08 UTC