Iranian websites, in English I'm sure. There's American websites that advocate all sorts of things that you must consider official US policy.Iranian state-owned websites have explained why the destruction of Israel and the slaughter of its population would be justified. Jews are referred to as "cattle."
Khamenei declared, “Iran’s position, which was first expressed by the Imam [Khomeini]…is that the cancerous tumor called Israel must be uprooted from the region.” A month later, he repeated his message. “The foundation of the Islamic regime is opposition to Israel and the perpetual subject of Iran is the elimination of Israel from the region.”
“Our battalions are named Imam Ali, Imam Hussein and Bayt al-Maqdis [Jerusalem] to clarify our final destination to the Basiji. We will not abandon our [armed] struggle until the annihilation of Israel and until we will be able to pray in al-Aqsa mosque.
About negotiating with Iran:
“The enemies are talking about the options [they have] on the table. They should know that the first option on our table is the annihilation of Israel.”
“The issue of Palestine is an Islamic issue. The Islamic world must come together to destroy the false Israeli regime….If this happens, nothing will be left of Israel.”
“If once the destruction and demise of occupying Israel was an impossible and unattainable dream, today thanks to the historic and intelligent actions of Imam Khomeini, it has become possible and is actually in the process of occurring.”
“The destruction of Israel is the idea of the Islamic Revolution in Iran and is one of the pillars of the Iranian Islamic regime. We cannot claim that we have no intention of going to war with Israel.”
As if that was not enough cause for concern, the International Atomic Energy Agency warned in a May 2011 report of Iranian efforts “involving the removal of the conventional high explosive payload from the warhead of the Shahab-3 missile and replacing it with a spherical nuclear payload.”