In his congratulatory message, Haniyeh felicitated Pezeshkian as the new president of the Islamic Republic of Iran.
"We and our people in Palestine have trust in your services to Iran, overcoming the challenges and hardships, moving towards the unity of the Islamic Ummah against our enemy and helping the pivotal issue of our Ummah," the senior Hamas official said.
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 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.
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