Netanyahu fired back at the Iranian president in an open letter to Israelis. (Downing Street/Creative Commons)

"As prime minister of Israel, the state of the Jewish people, I am working in every way in order that Iran does not have nuclear weaponry," Netanyahu said.

In an open letter to Israelis to mark the end of Yom Kippur, Netanyahu described the regime of Iran as one that "seeks at every opportunity to sentence us to death."

"On Yom Kippur eve, sacred to the Jewish people, the Iranian tyrant chose to call publicly before all of the world for us to vanish. This is a black day for those who chose to remain in the auditorium and hear these hateful words."

Iran has denied working secretly to develop nuclear weapons, saying that its atomic power program is peaceful. The U.S., Israel's strongest ally in opposing Iran's program, did not send a delegation to Ahmadinejad's General Assembly speech.

Ahmadinejad said his country was under constant threat of military action from "uncivilized Zionists" during his address to the United Nations Wednesday.

Read more of Neon Tommy's coverage of Iran here.

Reach Executive Producer Danny Lee here; follow him on Twitter here.