Zarif said Thursday after his meetings in Vienna with Catherine Ashton, foreign policy chief for the European Union, there are no plans to close nuclear sites in Iran.
"The way to ensure the peaceful nature of our program is not closing the sites, rather its peaceful nature should be displayed openly, transparently and based on the international regulations and supervision," he was quoted by the semiofficial Fars News Agency as saying.
Ashton is in Vienna leading talks aimed at finding a final solution to the nuclear impasse.
Iran under the terms of a six-month deal reached in November agreed to curb its nuclear research activity in exchange for modest relief from Western economic sanctions.
Iran says its nuclear program is for peaceful purposes, though the International Atomic Energy Agency said recently it wanted answers regarding Iran's research into a detonation device used in nuclear weapons.
Ashton said in a statement negotiations with Iran "won't be easy."
Another round of talks is scheduled March 17 in Vienna.