Zarif, who arrived in Madrid early Tuesday, made the announcement in a meeting in Madrid with his Spanish counterpart Jose Manuel Garcia-Margallo y Marfil and Javier Solana, a former European Union foreign policy chief.
He did not say where the talks will be held but earlier on Thursday Iran's deputy foreign minister and senior nuclear negotiator Abbas Araqchi said representatives from Iran and the Group 5+1 (Russia, China, the US, Britain, France and Germany) are likely to hold the next round of nuclear negotiations in the US city of New York.
Araqchi said there is a "strong possibility" that the talks will be held on the sidelines of the sessions of the United Nations Disarmament Commission (UNDC) in New York.
In their latest round of talks, on April 2, Iran and the Group 5+1 (also known as the P5+1 or E3+3) reached a framework nuclear agreement after more than a week of intensive negotiations in Lausanne, Switzerland, with both sides committed to push for a final, comprehensive accord until the end of June.
The framework provides a series of solutions that will be the basis of a comprehensive joint plan of action.