"I feel I have done my duty. I will vote alongside all of you for Rouhani," Jahangiri was quoted as saying by Tasnim news agency to his supporters in Fars province.
Jahangiri registered to run for the election amid concern among Rouhani's allies that the president might be disqualified by the Guardian Council, a clerical body that vets candidates based on their loyalty to the Islamic Republic.
(Reporting by Bozorgmehr Sharafedin; Editing by Hugh Lawson)
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