Iran's Supreme Leader Ayatollah Ali Khamenei warned on Monday during his Eid al-Fitr prayer sermon that the United States will receive a "strong counterattack" if it decides to attack Iran.

"They threaten to act maliciously, but if any act of aggression comes from them—the Americans and the Zionist regime—they will undoubtedly receive a strong counterattack. The Iranian nation will respond to the conspirators as it has until today," Khamenei said, noting that Israel's "routine assassination of figures" is supported by the United States and the Western governments.

Khamenei's warning comes after United States President Donald Trump threatened to attack Iran if the Middle Eastern country refuses to strike a nuclear deal with Washington, claiming that there would be "bombing the likes of which they have never seen before."