Tehran - Iranians were headed to the polls on Friday for the first presidential election since the landmark 2015 nuclear agreement, in a vote that could have serious implications for the future of the country and its relationship with the West.

President Hassan Rouhani, a moderate, was seeking a second term as he faced off against Ebrahim Raisi, the frontrunner among the conservative set.

The position of president is the second most powerful in Iran after the Supreme Leader, who is commander-in-chief and controls the Guardian Council. The May 19 vote will be the first stage, with a possible runoff vote if none of the candidates wins a simple majority of 50 percent +1 of the votes.

All voting is to be concluded before the start of the holy month of Ramadan.