Moderate cleric Hassan Rowhani has assumed Iran's presidency with supreme leader Ayatollah Ali Khamenei officially endorsing him.
"There is a clear message in electing a competent individual with more than three decades of service to the (Islamic republic's) establishment," Khamenei said in a statement on Saturday.
"The message is of loyalty to the (Islamic) revolution, hope in the establishment ... and trust in individuals determined to add to its success and reduce problems" in Iran, he added.
Khamenei said Rowhani, 64, "hails from the clerical stronghold which has confronted the enemies".
He called on the new president to "defend the goals of the Islamic establishment and the rights of the nation, and to stand up to arrogance and bullies", in reference to Western powers.
Rowhani begins his term as the Islamic republic's seventh president facing challenges over its ailing economy and international isolation due to the controversial policies of his hardline predecessor, Mahmoud Ahmadinejad.
Rowhani's public inauguration will take place on Sunday when he takes the oath of office in parliament.
He defeated several conservative rivals in the June 14 presidential election, having pledged to resolve tensions with world powers and shore up an economy hit hard by international sanctions.
