Iranian Foreign Minister Mohammad Javad Zarif will fly to Vienna on Friday evening for talks with six major powers aimed at sealing a final deal on Tehran's nuclear program, Iranian agencies reported on Thursday.
US Secretary of State John Kerry will also fly to Vienna on Friday, the State Department said.
"The head of Iran's nuclear delegation will depart for Vienna on Friday evening to join the negotiating team," the ISNA agency reported.
The major powers in the talks - Britain, China, France, Germany, Russia and the United States - reached a framework accord with Iran in April. A deadline of June 30 was set for the deal, but negotiations are widely expected to slide past that date.
Zarif met with his European counterparts in Luxembourg on Monday and said he saw a good chance of reaching a final agreement by the deadline or a few days later.