From Israel Today, Thursday, January 28, 2010:
...During a meeting [on Tuesday 26 January 2010] with the visiting Mauritanian president, [Iran's supreme leader, Ayatollah Ali] Khamenei said: "Definitely, the day will come when nations of the region will witness the destruction of the Zionist regime. How soon or late that will happen depends on how Islamic countries and Muslim nations approach the issue."
...In recent years, Khamenei has referred to Israel as a "cancerous tumor" that must be removed from the Middle East.
Khamenei's views on Israel are identical to those of Iranian President Mahmoud Ahmadinejad. With Iran's spiritual and civilian leadership so opposed to the existence of the Jewish state, Israel has no choice but to view the Islamic Republic's efforts to obtain nuclear weapons as an existential threat.