Washington: US President Donald Trump issued a stern ultimatum to Tehran on Sunday, warning of an unprecedented military response should Iran follow through on its vow to retaliate for the joint U.S.-Israeli strikes that killed Supreme Leader Ayatollah Ali Khamenei.

In a post on his Truth Social platform, Trump cautioned that any further escalation by the Islamic Republic would be met with a "force that has never been seen before."

"Iran just stated that they are going to hit very hard today, harder than they have ever hit before. They better not do that, however, because if they do, we will hit them with a force that has never been seen before," the president wrote.

 

Tehran Vows "Punishment"

The warning followed a defiant broadcast by Iran's Press TV, which characterised the killing of the 86-year-old cleric as a "crime of assassination" that "will not go unpunished." The state-aligned outlet asserted that the "pure blood of the martyred Leader will uproot the criminal regimes of the US and Israel."

According to the Tasnim News Agency, Khamenei was killed in the early hours of Sunday while at his workplace. Confirming the death, the leader’s official Farsi-language social media account posted a verse from the Quran (Surah Al-Ahzab, 33:23) honouring those who have "fulfilled their vow [by death]" to Allah.

A Nation in Mourning and Stasis

Iran has entered 40 days of public mourning, a period known as Arba'een in Shia Islam that carries immense spiritual significance. Observers noted that the lengthy mourning period provides the clerical establishment a vital window to manage a transition of power behind closed doors amid the chaos of "Operation Epic Fury" and "Operation Lion's Roar."

State media has moved to frame the leader's death not as a military defeat but as the "Martyrdom of the Guardian"—a final sacrifice for Iranian sovereignty. Since succeeding the revolution’s founder, Ruhollah Khomeini, in 1989, Khamenei’s tenure was defined by unwavering opposition to Western influence.