Zarif arrived in the Austrian capital on Monday evening to take part in the ISSG meeting, which is scheduled to be held on Tuesday.
Upon his arrival, the Iranian foreign minister held talks with de Mistura over the latest developments in Syria and the ISSG meeting.
The two sides also discussed the measures taken so far by the UN to deliver relief aid to the Arab country.
Iran, Russia, Turkey and Saudi Arabia as well as representatives from the European Union and the Arab League are among the countries participating in the meeting.
The 17-nation ISSG aims to discuss the stalled negotiations, challenges in maintaining the February ceasefire and the delivery of UN humanitarian aid to various areas across the war-stricken country.
Syria has been gripped by foreign-backed militancy since March 2011. UN Special Envoy for Syria Staffan de Mistura estimates that over 400,000 people have been killed in the conflict, which has furthermore displaced over half of Syria’s pre-war population of about 23 million.