Polling ended at midnight local time in Iran (6.30am Saturday AEST) after being extended three times for a total of six hours.Â
The interior ministry said initial reports showed the turnout was around 50 per cent, higher than the first round. The final result will be announced early on Saturday, the interior ministry said.
The run-off follows a June 28 ballot with a historically low turnout, when more than 60 per cent of Iranian voters abstained from the snap election for a successor to Ebrahim Raisi, following his death in a helicopter crash.
Iranian presidential candidate Saeed Jalili (centre) backs closer ties with Russia and China. (EPA PHOTO)
The vote is a tight race between low-key lawmaker Masoud Pezeshkian, the sole moderate in the original field of four candidates, and hardline former nuclear negotiator Saeed Jalili, a staunch advocate of deepening ties with Russia and China.
While the election is expected to have little impact on the Islamic Republic's policies, the president will be closely involved in selecting the successor to Ayatollah Ali Khamenei, Iran's 85-year-old supreme leader who calls all the shots on top matters of state.
"I have heard that people's zeal and interest is higher than in the first round. May God make it this way as this will be gratifying news," Khamenei told state TV after casting his vote.
Khamenei acknowledged on Wednesday "a lower than expected turnout" last week, but said "it is wrong to assume those who abstained in the first round are opposed to Islamic rule".
The election coincides with escalating Middle East tensions due to the war between Israel and Iranian allies Hamas in Gaza and Hezbollah in Lebanon, as well as increased Western pressure on Iran over its fast-advancing uranium enrichment program.
