Saudi Arabia's King Salman bin Abdulaziz and the Saudi Crown Prince, Mohammed bin Salman congratulated Iranian president-elect Masoud Pezeshkian over his victory in Iran's snap presidential election.

"We wish good health and happiness for Mr. Pezeshkian, and we wish more and more progress for the brotherly nation of Iran," Saudi king wrote.

"We are eager to continue the development of relations between the two countries and our brother nation and to continue coordination in order to promote regional and international security and peace," he added.

"We emphasize our desire to develop and deepen relations between the two countries," Bin Salman said.

Earlier, the officials of other countries, including Syria, Pakistan, Russia and Iraq, had also congratulated Pezeshkian on his victory in the second round of Iran's presidential elections.

Veteran parliamentarian Masoud Pezeshkian has won Iran's runoff presidential vote, the interior ministry says, bringing a conclusion to a tight race that saw voters swell polling stations on Friday.

Pezeshkian received more than 16 million votes against former nuclear negotiator Saeed Jalili with more than 13 million out of over 30 million votes cast, electoral authorities said.

"By gaining a majority of the votes cast on Friday, Pezeshkian has become Iran's next president," the interior ministry said.

The runoff on Friday followed a June 28 ballot in a snap election to find a successor to President Ebrahim Raeisi who lost his life with his foreign minister Hossein Amir-Abdollahian and others in a helicopter crash in northwest Iran.

Pezeshkian originally ran against a field of five candidates last week, winning the largest number of votes but falling short of a majority which sent him and Jalili to a second round.