Iran’s Supreme Leader Ayatollah Ali Khamenei has called on Muslims around the world to unite and “stand by the people of Lebanon and the proud Hezbollah”, following reports of the killing of the Lebanese group’s leader Hassan Nasrallah in an Israeli air strike on Friday.

In a statement issued on Saturday following Israel’s claim of the killing of Nasrallah, Khamenei described Israel’s policy as “short-sighted” and called the deadly strikes on Lebanon “criminal”.

“The Zionist criminals need to know that they are far too weak to be able to inflict any significant damage on the solid structure of Lebanon’s Hezbollah,” he said in a statement that was also posted on X.

“The massacre of the defenceless people in Lebanon once again … proved the short-sighted and stupid policy of the leaders of the usurping regime,” Khamenei added.

Iran’s leader did not mention Nasrallah’s fate, but a statement from Hezbollah later on Saturday confirmed Nasrallah’s death.

Khamenei stopped short of calling for revenge, and instead declared that Israel would “regret its actions”.

“The fate of this region will be determined by the forces of resistance, with Hezbollah at the forefront,” he added without saying what steps Iran would take next.

According to reports, Khamenei called for an emergency security meeting on Saturday to discuss the latest developments in Lebanon.

Hezbollah is a close ally of Iran, and the death of Nasrallah is a major blow to Iranian influence in the region, analysts say.

Tohid Asadi, an American studies expert at Tehran University, told Al Jazeera that Khamenei’s statement “is a clear sign of solidarity” towards Hezbollah and the fight for the Palestinian cause against Israel.

“There’s no plan of action so far in this message … We have to wait for hours and days to see what takes place on the ground,” Asadi said, describing the latest developments in Lebanon as “very tragic as far as Hezbollah and Iran are concerned”.

Despite the latest bombardments, Iranian political analyst Mohammad Marandi said it is “clear” that Israel “still cannot defeat” the Lebanese armed group militarily.

“I think Israel is underestimating what it is up against,” Marandi, who is in Beirut, told Al Jazeera, adding that most of Lebanon is united against the “barbaric” military operation of Israel.

“The savagery that we are seeing, murdering hundreds of people a day in Beirut and elsewhere, is only going to spark anger across the Global South” against Israel and the West, he added.

Marandi predicted developments in the coming days that Israel “will not be expecting”.

“Hezbollah has thousands of many young commanders who have been trained and prepared for many years now,” he said.