"#IranDeal is not a ceiling but a solid foundation. We must now begin to build on it," Zarif wrote on his Twitter account.
Iran and the Group 5+1 concluded more than two weeks of talks over Tehran's nuclear program in Vienna on Tuesday in a final round a senior Iranian lawmaker described as "successful".
The negotiating parties reached a conclusion over the text of a comprehensive deal on the nuclear issue after 22 months of talks.
In a joint statement, EU High Representative Federica Mogherini, who has been coordinating diplomacy with Iran on behalf of the six powers, and Iranian Foreign Minister Javad Zarif, referred to Tuesday as an historic day.
"It is a great honour for us to announce that we have reached an agreement on the Iranian nuclear issue," the statement said, adding that "With courage, political will, mutual respect and leadership, we delivered on what the world was hoping for: a shared commitment to peace and to join hands in order to make our world safer. This is an historic day also because we are creating the conditions for building trust and opening a new chapter in our relationship."