President Rouhani left Tehran for Istanbul on Wednesday in order to take part at the Summit of the Organisation of Islamic Cooperation.
President was given farewell by First Vice-President Dr Eshaq Jahangiri, Adviser to the Supreme Leader on International Affairs Dr Ali Akbar Velayati and a number of ministers and vice-presidents.
The 13th Summit of the Organisation of Islamic Cooperation is scheduled to kick off on April 14 and 15 in Istanbul.
Combatting terrorism and extremism is one of the issues to be discussed in the summit.