Iranian President Hassan Rouhani, cast his vote in the country’s presidential election on the morning of Friday, May 19, at Tehran’s Hosseiniyeh Ershad mosque.

Rouhani is a 68-year-old cleric, who is seen as moderate within Iran’s political system. He negotiated the historic 2015 nuclear deal involving six global leaders led by the US.

Rouhani is running against three candidates, and his primary opponent is Ebrahim Raisi, 56, a hardline cleric and former prosecutor who is close to Supreme Leader Ayatollah Ali Khamenei, as reported by BBC.

To win the election a candidate must receive over 50 percent of the vote, otherwise a runoff will be held next week. More than 54 million Iranians are eligible to vote, according to BBC.

The New York Times reported that the election is largely viewed as a referendum on Rouhani’s moderate policies.