After the US president demanded Tehran's"unconditional surrender", Iran's Supreme Leader Ayatollah Ali Khamenei vowed on Wednesday that his country would show no mercy to Israel's rulers.

"We must give a strong response to the terrorist Zionist regime. We will show no mercy to the Zionists," Khamenei wrote on the "X" platform.

The Iranian leader also pointed to statements by US President Donald Trump, saying that those who know Iran and its history"know that Iranians do not respond well to threatening language."

"And Americans should know that any US military intervention will undoubtedly be accompanied by irreparable consequences," he threatened.

A powerful American bunker-penetrating bomb capable of destroying Iran's nuclear facilities hidden deep underground is the only weapon President Donald Trump would likely choose if he decided to support Israel militarily.

Israel has set itself the goal of preventing Iran from developing nuclear weapons, but it does not have a bomb in its arsenal like the 13,607-kilogram GBU-57 warhead, which can penetrate 61 meters underground and explode.

Israel's defense minister on Wednesday fueled speculation that the campaign against Iran, now in its sixth day, aims not only to stop Iran's nuclear program but also to overthrow its leadership.

“Symbols of power are being bombed and destroyed – first the Broadcasting Service, and soon other targets – and crowds of people are fleeing,” Defense Minister Israel Katz wrote on the X platform. “This is how dictatorships collapse.”