Iran's Former Head of Hassan Rouhani's Presidential Office and Chief of Staff Mahmoud Vaezi backed presidential candidate Masoud Pezeshkian and criticised his rival's foreign policy, conservative presidential candidate Saeed Jalili, during an interview filmed on Tuesday.

"Mr. Pezeshkian believes we should decrease hostilities and increase friendship. Logically, our foreign policy should not be a tension-generation concept," Vaezi said.

"If [Presidential candidate Saeed Jalili] is elected our foreign relations will be more complicated than they are right now. Also, he has always been against the JCPOA and has a special approach toward the West, a very strict one. Thus, regarding foreign policy, there are two contrasting viewpoints," he continued.

Vaezi also suggested that Pezeshkian's approach to foreign policy could help end several conflicts in the region 'through dialogue', including in Syria and the war in Yemen.

"[Pezeshkian] thinks competition between regional countries shouldn't allow countries out of the region to provoke division between them. We can settle our differences ourselves," he added.

The results from the first round of the election show that Pezeshkiyan received 42 percent of the vote, while Jalili garnered 39 percent.

The second round of the election is scheduled for 5 July after neither candidate secured a majority in what was reportedly the lowest turnout election since the country's 1979 revolution.

The election was held a year ahead of schedule due to the 19 May helicopter crash that killed President Ebrahim Raisi, Foreign Minister Hossein Amirabdollahian and six others in the northwestern mountains.