ISTANBUL, JUNE 10 - German Foreign Minister Heiko Maas is in Tehran for talks with the Iranian authorities on the 2015 nuclear agreement. The Berlin envoy arrived late yesterday evening in the capital of the Islamic Republic, where he will meet today President Hassan Rohani and his counterpart Mohammad Javad Zarif. In the past few hours, Zarif reiterated that if Europe wants to save the agreement it must "normalize economic relations" with its country. Maas' visit opens a crucial week for diplomatic efforts aimed also at starting a possible mediation with the United States, and Japanese Prime Minister Shinzo Abe will also arrive in Tehran on Wednesday. Meanwhile, Iran's Foreign Ministry spokesman, Abbas Mousavi, warns: Iran will not discuss issues that go beyond the agreement and the EU is not in a position to question Iran's actions outside of that".