We are trying to remove some remaining misunderstandings, Zarif told reporters, adding but there are still some disagreements on some issues.
He further stressed that the results are not still definite.
He also asked the people attending the ceremony to pray for the outcome which would serve the interests of the nation, Muslims and Islam.
Ramadan is the blessed month of holy Quran’s revelation, Qadr nights (the nights of the 19th, 21st and 23rd Ramadan), praying and an invitation to God’s feast.
Zarif along with Head of Atomic Energy Organization of Iran Ali-Akbar Salehi and President's special aide Hossein Fereydoun is in Vienna for nuclear talks with the six world powers.
Iran, the European Union and representatives of the P5+1 have been holding intensive nuclear talks to reach a final agreement on Iran's nuclear issue.
Both sides are to find a solution for a nuclear dispute that goes back to over a decade.The talks have been extended for a week which is July 7.