Hassan Nasrallah said those who hope the anti-government protests in Iran would grow and lead to regime change will be left disappointed.
The head of Lebanon's powerful Tehran-backed Hezbollah movement said on Wednesday he was confident protests in Iran would be brought under control and leave US President Donald Trump disappointed.
"There is nothing to worry about and what happened in Iran is well contained," Hassan Nasrallah said in an interview to Al Mayadeen, a TV channel close to his movement.
Iran's Revolutionary Guards chief proclaimed the "end of the sedition" on Wednesday as tens of thousands of people rallied in a show of solidarity with the government.
Protests over economic problems broke out in Iran's second city Mashhad last week and quickly spread across the country, turning against the regime as a whole.
The rare protests drew vocal support from Trump, who on Wednesday vowed to back demonstrators and called the Iranian "brutal and corrupt."
"Trump's hopes have been disappointed," Nasrallah said, as will the hopes of "all those who bet that the protests would grow and lead to the fall of the regime and chaos in Iran."
He said he saw no risk of a change in Tehran's policy of support for movements such as his but when asked about Iran's financial contributions to Hezbollah, he replied "no comment."
Nasrallah also said the Syrian war, now in its seventh year, will be finished in one or two years at most, adding Israeli strikes on Hezbollah positions in Syria did not, and will not, prevent supplies of weapons reaching the group.
Hezbollah and other Iran-backed groups have backed Syria's regime leader Bashar al Assad during the conflict which erupted in 2011.