Ayatollah Ali Khamenei spoke for the first time since the turmoil percolated from last Friday's presidential election in which President Mahmoud Ahmadinejad was declared the landslide winner over his nearest challenger, Mir Hossein Mousavi, prompting cries of vote fraud and huge daily protests.
"Today the Iranian nation needs calm," Khamenei told tens of thousands of Iranians who gathered in and around Tehran University to hear his prayer sermon, The Times of London reported.
"The people have chosen whom they wanted," Khamenei said in the sermon, attended by Ahmadinejad, that was broadcast live around the world.
Khamenei also called for an end to the protests that have rocked the Middle Eastern country since Saturday, The New York Times reported.
"Street challenge is not acceptable. ... This is challenging democracy after the elections," he said. "It would be wrong to think that turning out on the street would force officials to accept their demands."
He also urged dissenters to to seek a remedy through legal channels, saying the turnout -- officially 85 percent -- showed the ballot reflected the nation's will. Khamenei also endorsed Ahmadinejad's policies and said the margin of victory, reported by Ahmadinejad's tally at 11 million, was so great it could not have been falsified.
"The Islamic republic state would not cheat and would not betray the vote of the people," the supreme leader said.
Iranian media outlets reported eight people died during the protests that sometimes turned violent. On Thursday, tens of thousands of black-clad protesters clogged Tehran streets to honor those who had died or were injured.