Iranian Foreign Minister Mohammad Javad Zarif will travel to Vienna on Saturday to join a final push for a comprehensive nuclear agreement with major powers, state media reported.
"On Saturday morning, he will join his deputies who are at the talks drafting the text of a comprehensive agreement," the official IRNA news agency reported on Thursday.
US Secretary of State John Kerry, who is to join the talks on Friday, called on the Iranian side to address all outstanding issues.
"If they are not addressed, there won't be a deal," he stressed.
Iran and the six powers are working to a June 30 deadline to allay international fears that it is seeking a nuclear weapons capability.
Iran denies any such ambition but is eager to secure a lifting of crippling Western economic sanctions imposed over those concerns.
On Tuesday, Iran's supreme leader Ayatollah Ali Khamenei set out "red lines" for the negotiations, demanding an "immediate" lifting of sanctions by the United States as well as the United Nations in any deal.
He also renewed his opposition to any inspection of Iranian "military sites" by the UN watchdog.