Zarif held discussions with his Turkish counterpart, Ahmet Davutoglu, and President Abdullah Gul in Istanbul, the Turkish newspaper Daily Hurriyet reported. He also met with Prime Minister Recep Tayyip Erdogan in Ankara.
"I believe sectarian conflict is even a greater threat, and it is not confined to one region," Zarif said at a news conference with Davutoglu. "If the flames of sectarianism rage in the Middle East, you will see the results in the streets of London, New York, Rome and Madrid."
Zarif, whose country faces sanctions because of its nuclear development program, described nuclear weapons as one of the greatest threats the world faces.
Davutoglu said Iran and Turkey are trying to work together to contain the Syrian conflict.
"Sitting here together with the Iranian foreign minister, you can be sure we will be working together to fight these types of scenarios which aim to see a sectarian conflict," he said.