In comments on Friday night, Rahmani Fazli said no ballot will be permitted to be cast after 12 o’clock at night.
The Interior Ministry has so far extended the voting three times. The polls were initially to close at 6 pm, but authorities extended voting until midnight.
The number of voters in Iran’s presidential election had surpassed 50 percent by late evening.
More than 56,400,000 Iranian people were eligible to vote.
The ballot count will begin as soon as the election process formally comes to an end.
There are four candidates seeking presidency in the polls, namely incumbent President Hassan Rouhani, Ebrahim Raisi, Mostafa Hashemitaba, and Mostafa Aqa-Mirsalim.
A run-off would be held a week later if none of the candidates wins a majority, which is at least 50 percent plus one vote.